101m4n

I mean like one of these:

Thanks! I'm afraid I was skimming and didn't notice the link. Welcome to the money-pit that is custom watercooling .
 
 
In that case, the right angle fittings should be fine. Just make sure they aren't under tension when the tubes are installed and you'll be set .
 
In the case of hardline, one thing I will suggest is to avoid tubes with more than one bend in them wherever you can. Like the one from your pump/res to the GPU in image 1, or the one from the GPU to the top radiator in image 2. In the case of image 1, If you rotate the fitting on the pump/res so that it goes straight up instead of off to the left, that bend will be a lot easier. Single right angle bends are easy, just bend and trim to match the fittings. Multiple bend runs are a nightmare, as it's very hard to control the distance between the two bends. You may be able to do this if you measure very carefully and use a jig of some sort to ensure a fixed bend radius, but if you are bending by eye it will be very difficult. I'm guessing you are planning on using spacers to connect the right angle fittings on the CPU to the top radiator? If so, that will save you a lot of time and effort.
 
Another thing you can see in this picture is that we used a couple of rotary fittings to give ourselves some wiggle-room on the radiator -> CPU bend. So that's another tool you can use to make the tough bends easier.
 
Lastly, wait for big navi  (if you can). Even if it's not as good as nvidias offerings, if it's even a little competitive it could prompt nvidia to lower their prices a bit.

I'd use the first one as it keeps the slots below the GPU free for other expansion cards. I actually did a build with this exact layout a few years ago. It worked out pretty well (aesthetically speaking). Performance wise, it's probably better to do pump -> cpu -> gpu -> 420 -> 280 -> pump. IE: heat source -> exhaust radiator -> intake radiator. With your hardware though, these radiators should be plenty for your system regardless of the loop order .
 
Also, are you planning on using hard or soft tubing? In either case I'd advise avoiding rotary fittings wherever possible, but especially so with flexible tubing. Reason being if anything puts tension on the fitting it will eventually cause it to leak as one side of the internal o-ring is compressed. Also if you are going with soft tubing you can definitely skip the right angle fittings on the CPU block. Just connect the compression fittings directly to the block

As far as tube choices go, thicker tubes look nicer if you ask me. That being said, there is no appreciable performance loss with thinner tubes and thinner ones are much easier to work with. With thinner tubing for example, you shouldn't need the right angle fittings on the GPU block either.
 
Lastly, your board actually has a 2 pin temperature sensor header. Which means you can get a g1/4 temperature sensor and set up your fans to ramp with coolant temperature rather than CPU temperature, which is very nice  (especially with a GPU and CPU in the loop). Mine is a gradual ramp (20 to 40%) from 20 to 30 degrees, then an aggressive ramp from (40% to 100%) from 30 to 40. This would be noisy and annoying for a CPU cooler but it's great for a water cooling loop as the specific heat capacity of water is very high (it takes 4200 watts to raise the temperature of 1 litre of water by 1 degree in 1 second), and you don't really want your coolant getting that hot anyway.
 
Now, I should probably get back to my work!
Best of luck with the build

I have updated the OP to reflect the current status of the build, here are some images of the system so far!
 

 

 
Bending copper pipes properly is hard:
 

linus:

Thanks!
 
No I'm going for an all black build with ek zmt this time around, there are some pictures earlier in the thread.
Did consider doing copper again, but I wanted something more practical (and lower effort 😆).
Just as well, with the flexible tubes I didn't have to empty the loop to remove the motherboard!
I'm also not watercooling the GPU, as it's an old card from another machine and I wouldn't mind a ray-tracing capable one at some point in the future. If I get a new GPU for it, then I will likely watercool that (which the soft tubes will also make easier). I'll be waiting for AMDs answer to rtx3000 before I make any decisions though.
 
Incidentally, the copper build actually belonged to a friend, he moved out of the country at the beginning of the year and disassembled that system. I bought some of the components from him and they are actually being used here, namely; the pump-res, power supply and a few right angle fittings.

I last replaced my rig in 2015. It was a water-cooled ncase-m1 build with a 4790k and a gtx970. She was a beautiful machine, but she's getting a little long in the tooth now.
Anyway, about a week ago, I found a good deal on a used 3960x and trx40 motherboard. I decided to place a bid, and if I got the parts at a decent price I'd go forward with the build.
I'm here so you can probably guess what happened. Ended up getting the board and CPU for £1100!
 
The planned specs are as follows:
3960x Gigabyte trx40 aorus master 64GB 3600mhz memory 500GB sabrent rocket pcie4.0 ssd Fractal design s2 meshify (because I did another build here on the forum in a fractal case and I thought it was pretty solid) MSI gtx 1080 gaming-X (as I already have it, and I don't really need anything faster) Custom loop! (because building a PC without one is no fun at all) The plan is to update the build as it unfolds over the next few days, adding posts to the thread and updating the OP as things progress.
 
[Sunday 20/09/2020]
I have some of the parts in hand already and the rest should arrive tomorrow.

I don't actually have any ddr4 on hand (all my systems are too old for that) so I won't know until tomorrow if the secondhand CPU/Motherboard I have been sold are any good! 🤞
 
[Later that same evening...]
Well that didn't take long.
The first bit of drama I've run into is that the CPU came without the orange carrier tray or shmansy AMD torque wrench. This is all I got:

Quick google reveals that it's a t20 driver with a torque of 1.5 newton-metres. It looks like the carrier frame isn't actually load-bearing, and is just there to make inserting/removing the processor safer (less likely to accidentally break the socket). Also the CPU has notches in it, like any other processor, which engage with the socket when it's inserted. So it looks like the carrier frame isn't responsible for aligning the pins either.
I managed to get it installed with this thing, which I originally bought for installing disk breaks on my mountain bike:

It's pretty crude, but at least I know all the screws should be roughly the same tightness (and at least somewhere close to 1.5NM).
The board and CPU after a little cleaning:

On another note, the motherboard doesn't seem to have been very well taken care of. There are some missing screws, three for the backplate and another for the first m.2 slot. Hopefully I can give it a better home that it had previously, tsk tsk.
That being said, I'm even more apprehensive about turning the thing on now...
 
[Monday 21/09/2020]
Did a post test (without cooling), and all was well. A weight off my mind for sure.
Time to get this show on the road:

 
P.S. Thanks ocuk, I love it when my harribo comes with free watercooling parts 
 
So the radiators came with two sets of longs screws, some too long for the fans+panel, and some that were too short.
I don't think these radiators are intended to be installed like this (mounted to a panel through the fans). But I liked the way it looks, and I managed to make it work in the end:

This also gives the top fans a little more clearance, which can only be a good thing.
The current status of the build:

 
[Tuesday 21/09/2020]
I was up working up until about 3 in the morning last night working on the build, this is how it looks now:

Unfortunately, it doesn't hold air. Worse still, it's a relatively slow leak which means I'm going to have to hunt for it a bit...
First things to check as usual, rotary fittings.
 
I had to use different tubing for the fill port connection as the black stuff wouldn't bend enough:

Oh well, still looks fairly nice
 
[Tuesday evening]
So I found the leak, it was the right angle fitting at the bottom of the pump. I replaced it with a clear tube and put the ball valve at the end:

And on the back:

The tube is old and a little manky, but it's out of sight so I'm not too bothered. There aren't any clamps, but these barbs are actually meant for larger tubes, so they'll hold. Certainly took some doing to get them on there.
Time for a leak test:

Wish me luck 😬
 
[A bit later]
Disaster has struck.
 
The filling of the loop went off without a hitch, no problems there. But while I was bleeding it, I got the bright idea to connect the top fans to the external power supply I was using to power the pump. No particular reason, just wanted to see them spin, maybe get a feel for the amount of airflow. The fan controller though was connected to the motherboard with a 12v and ground via a system fan header, so I can only assume the board saw 12v and a path to ground and promptly tried to start up. There was a pop, some magic smoke escaped from somewhere near the system fan header, and that was that.
I have been building systems for almost ten years and I have made plenty of mistakes, but this is the first time I've killed a motherboard 😪. As this is my fault, I consider myself morally obliged to eat the cost of a replacement board.
All in all, a bad day.
I have tested as many other components as I can, PSU, memory, SSD, and they are all fine which is a good sign. The GPU wasn't installed at the time either so that's fine too. But the big ticket item is the CPU. I have no way to test it, and if it's dead, then my day will get a lot worse.
 
Moral of the story:
Be very careful when using an external power supply to power components in your PC. Make sure that any components you connect it to are completely disconnected from the rest of the system. If they are not, you are in for a bad time.
 
[Wednesday 23/09/2020]
I have taken it out of the system now and found the borked chip:

The serial number is 3947s934gb, made by nuvoton. There are several of them on the board, they appear just to be fan controllers.
If that's the only damage, it might be repairable 🤔
 
[Thursday 24/09/2020]
New board has arrived. This evening I'll get it installed, hopefully I can polish off the build without killing this one.

Even at the cost of a new motherboard, I'm actually still £150 below retail price on the motherboard and processor. Fingers crossed the CPU isn't damaged.
 
[Later that evening]
The system works now, but there are more issues. 
 
The first is that the fans have very little clearance on their front face and scrape against the metal on the radiator and case at higher RPMs. So I'm going to have to remount them with the spacers on the other side. I have done this for the front radiator, but the top radiator will be a little more difficult. I may have to drill the threads out of the nuts I was using as spacers.
 
The other issue is the GPU. The machine simply refuses to post with it installed.
I have tried other GPUs (an rx550, and a gtx680) and they work fine.
I have tried the 1080 in other systems, and it works fine. I even tried it in an am2+ board from 2009 and it worked perfectly!
I have measured the pcie power cables with a voltmeter to check that the card is getting power. It is.
I have tried updating the motherboard bios.
I tried the GPU with every past bios that has ever existed for it. No luck.
This is actually a problem that I have had before with this card. Another board a couple years ago, an (also gigabyte) gaz68xp-ud3p also refused to post with the GPU installed. I'm beginning to think this is some sort of weird bios bug that only presents itself with MSI GPUs and gigabyte motherboards. It could also explain why there are so many MSI gaming X cards from this generation on ebay. And why they seem to be cheaper than the others.
Whatever it is, it must be something pretty fundamental to have spanned 9 years of hardware. To top it all off, the post code I get with the card installed (0D) isn't even in the manual! Just fantastic.
 
[Friday 25/09/2020]
So I picked up a replacement card on ebay and it seems to be working properly. The plan is to sell the old one to cover the cost.
The evga card works.
 
I have seen many reports of 10 series cards not posting in various motherboards and a disproportionate number of those issues seem to be with MSI cards. I pretty sure they just guffed up the bios on these cards somehow. Oh well, I suppose I'll just include a note and a return postage label with the card when I sell it.
 
Here's the system now:

Not without some more issues though (why not?).
One of the things I wanted was fan control via coolant temperature. Fortunately the board supports this with a couple of headers for 10k thermistors. For reasons that defy all logic and sense though, certain fans can only be controlled by certain sensors. The sensor that suited my needs however, was sandwiched between the edge of a usb2 header and the bottom-most PCIe slot.
I ended up having to solder some new leads on that would fit in the gap:

Can't say I was thrilled about soldering this close to by far the most valuable computer I have ever owned, but hey ho. It had to be done. I'm sure the cardboard will protect it from the 250 centigrade molten metal 😆.

Time to get an OS installed 😉:

New board has arrived. This evening I'll get it installed, hopefully I can polish off the build without killing this one.

Even at the cost of a new motherboard, I'm actually still £150 below retail price on the motherboard and processor. Fingers crossed the CPU isn't damaged.

Yup, it's solid stuff.
On an unrelated note, I actually distilled the coolant myself while I was waiting for parts:

Certainly not very practical, and I burned myself a few times, but good fun

Yup, it's solid stuff.
On an unrelated note, I actually distilled the coolant myself while I was waiting for parts:

Certainly not very practical, and I burned myself a few times, but good fun

I last replaced my rig in 2015. It was a water-cooled ncase-m1 build with a 4790k and a gtx970. She was a beautiful machine, but she's getting a little long in the tooth now.
Anyway, about a week ago, I found a good deal on a used 3960x and trx40 motherboard. I decided to place a bid, and if I got the parts at a decent price I'd go forward with the build.
I'm here so you can probably guess what happened. Ended up getting the board and CPU for £1100!
 
The planned specs are as follows:
3960x Gigabyte trx40 aorus master 64GB 3600mhz memory 500GB sabrent rocket pcie4.0 ssd Fractal design s2 meshify (because I did another build here on the forum in a fractal case and I thought it was pretty solid) MSI gtx 1080 gaming-X (as I already have it, and I don't really need anything faster) Custom loop! (because building a PC without one is no fun at all) The plan is to update the build as it unfolds over the next few days, adding posts to the thread and updating the OP as things progress.
 
[Sunday 20/09/2020]
I have some of the parts in hand already and the rest should arrive tomorrow.

I don't actually have any ddr4 on hand (all my systems are too old for that) so I won't know until tomorrow if the secondhand CPU/Motherboard I have been sold are any good! 🤞
 
[Later that same evening...]
Well that didn't take long.
The first bit of drama I've run into is that the CPU came without the orange carrier tray or shmansy AMD torque wrench. This is all I got:

Quick google reveals that it's a t20 driver with a torque of 1.5 newton-metres. It looks like the carrier frame isn't actually load-bearing, and is just there to make inserting/removing the processor safer (less likely to accidentally break the socket). Also the CPU has notches in it, like any other processor, which engage with the socket when it's inserted. So it looks like the carrier frame isn't responsible for aligning the pins either.
I managed to get it installed with this thing, which I originally bought for installing disk breaks on my mountain bike:

It's pretty crude, but at least I know all the screws should be roughly the same tightness (and at least somewhere close to 1.5NM).
The board and CPU after a little cleaning:

On another note, the motherboard doesn't seem to have been very well taken care of. There are some missing screws, three for the backplate and another for the first m.2 slot. Hopefully I can give it a better home that it had previously, tsk tsk.
That being said, I'm even more apprehensive about turning the thing on now...
 
[Monday 21/09/2020]
Did a post test (without cooling), and all was well. A weight off my mind for sure.
Time to get this show on the road:

 
P.S. Thanks ocuk, I love it when my harribo comes with free watercooling parts 
 
So the radiators came with two sets of longs screws, some too long for the fans+panel, and some that were too short.
I don't think these radiators are intended to be installed like this (mounted to a panel through the fans). But I liked the way it looks, and I managed to make it work in the end:

This also gives the top fans a little more clearance, which can only be a good thing.
The current status of the build:

 
[Tuesday 21/09/2020]
I was up working up until about 3 in the morning last night working on the build, this is how it looks now:

Unfortunately, it doesn't hold air. Worse still, it's a relatively slow leak which means I'm going to have to hunt for it a bit...
First things to check as usual, rotary fittings.
 
I had to use different tubing for the fill port connection as the black stuff wouldn't bend enough:

Oh well, still looks fairly nice
 
[Tuesday evening]
So I found the leak, it was the right angle fitting at the bottom of the pump. I replaced it with a clear tube and put the ball valve at the end:

And on the back:

The tube is old and a little manky, but it's out of sight so I'm not too bothered. There aren't any clamps, but these barbs are actually meant for larger tubes, so they'll hold. Certainly took some doing to get them on there.
Time for a leak test:

Wish me luck 😬
 
[A bit later]
Disaster has struck.
 
The filling of the loop went off without a hitch, no problems there. But while I was bleeding it, I got the bright idea to connect the top fans to the external power supply I was using to power the pump. No particular reason, just wanted to see them spin, maybe get a feel for the amount of airflow. The fan controller though was connected to the motherboard with a 12v and ground via a system fan header, so I can only assume the board saw 12v and a path to ground and promptly tried to start up. There was a pop, some magic smoke escaped from somewhere near the system fan header, and that was that.
I have been building systems for almost ten years and I have made plenty of mistakes, but this is the first time I've killed a motherboard 😪. As this is my fault, I consider myself morally obliged to eat the cost of a replacement board.
All in all, a bad day.
I have tested as many other components as I can, PSU, memory, SSD, and they are all fine which is a good sign. The GPU wasn't installed at the time either so that's fine too. But the big ticket item is the CPU. I have no way to test it, and if it's dead, then my day will get a lot worse.
 
Moral of the story:
Be very careful when using an external power supply to power components in your PC. Make sure that any components you connect it to are completely disconnected from the rest of the system. If they are not, you are in for a bad time.
 
[Wednesday 23/09/2020]
I have taken it out of the system now and found the borked chip:

The serial number is 3947s934gb, made by nuvoton. There are several of them on the board, they appear just to be fan controllers.
If that's the only damage, it might be repairable 🤔
 
[Thursday 24/09/2020]
New board has arrived. This evening I'll get it installed, hopefully I can polish off the build without killing this one.

Even at the cost of a new motherboard, I'm actually still £150 below retail price on the motherboard and processor. Fingers crossed the CPU isn't damaged.
 
[Later that evening]
The system works now, but there are more issues. 
 
The first is that the fans have very little clearance on their front face and scrape against the metal on the radiator and case at higher RPMs. So I'm going to have to remount them with the spacers on the other side. I have done this for the front radiator, but the top radiator will be a little more difficult. I may have to drill the threads out of the nuts I was using as spacers.
 
The other issue is the GPU. The machine simply refuses to post with it installed.
I have tried other GPUs (an rx550, and a gtx680) and they work fine.
I have tried the 1080 in other systems, and it works fine. I even tried it in an am2+ board from 2009 and it worked perfectly!
I have measured the pcie power cables with a voltmeter to check that the card is getting power. It is.
I have tried updating the motherboard bios.
I tried the GPU with every past bios that has ever existed for it. No luck.
This is actually a problem that I have had before with this card. Another board a couple years ago, an (also gigabyte) gaz68xp-ud3p also refused to post with the GPU installed. I'm beginning to think this is some sort of weird bios bug that only presents itself with MSI GPUs and gigabyte motherboards. It could also explain why there are so many MSI gaming X cards from this generation on ebay. And why they seem to be cheaper than the others.
Whatever it is, it must be something pretty fundamental to have spanned 9 years of hardware. To top it all off, the post code I get with the card installed (0D) isn't even in the manual! Just fantastic.
 
[Friday 25/09/2020]
So I picked up a replacement card on ebay and it seems to be working properly. The plan is to sell the old one to cover the cost.
The evga card works.
 
I have seen many reports of 10 series cards not posting in various motherboards and a disproportionate number of those issues seem to be with MSI cards. I pretty sure they just guffed up the bios on these cards somehow. Oh well, I suppose I'll just include a note and a return postage label with the card when I sell it.
 
Here's the system now:

Not without some more issues though (why not?).
One of the things I wanted was fan control via coolant temperature. Fortunately the board supports this with a couple of headers for 10k thermistors. For reasons that defy all logic and sense though, certain fans can only be controlled by certain sensors. The sensor that suited my needs however, was sandwiched between the edge of a usb2 header and the bottom-most PCIe slot.
I ended up having to solder some new leads on that would fit in the gap:

Can't say I was thrilled about soldering this close to by far the most valuable computer I have ever owned, but hey ho. It had to be done. I'm sure the cardboard will protect it from the 250 centigrade molten metal 😆.

Time to get an OS installed 😉:

Yup, it's solid stuff.
On an unrelated note, I actually distilled the coolant myself while I was waiting for parts:

Certainly not very practical, and I burned myself a few times, but good fun

Disaster has struck.
 
The filling of the loop went off without a hitch, no problems there. But while I was bleeding it, I got the bright idea to connect the top fans to the external power supply I was using to power the pump. No particular reason, just wanted to see them spin, maybe get a feel for the amount of airflow. The fan controller though was connected to the motherboard with a 12v and ground via a system fan header, so I can only assume the board saw 12v and a path to ground and promptly tried to start up. There was a pop, some magic smoke escaped from somewhere near the system fan header, and that was that.
I have been building systems for almost ten years and I have made plenty of mistakes, but this is the first time I've killed a motherboard 😪. As this is my fault, I consider myself morally obliged to eat the cost of a replacement board.
All in all, a bad day.
I have tested as many other components as I can, PSU, memory, SSD, and they are all fine which is a good sign. The GPU wasn't installed at the time either so that's fine too. But the big ticket item is the CPU. I have no way to test it, and if it's dead, then my day will get a lot worse.
 
Moral of the story:
Be very careful when using an external power supply to power components in your PC. Make sure that any components you connect it to are completely disconnected from the rest of the system. If they are not, you are in for a bad time.

So I found the leak, it was the right angle fitting at the bottom of the pump. I replaced it with a clear tube and put the ball valve at the end:

And on the back:

The tube is old and a little manky, but it's out of sight so I'm not too bothered. There aren't any clamps, but these barbs are actually meant for larger tubes, so they'll hold. Certainly took some doing to get them on there.
Time for a leak test:

Wish me luck 😬

I was up working up until about 3 in the morning last night working on the build, this is how it looks now:

Unfortunately, it doesn't hold air. Worse still, it's a relatively slow leak which means I'm going to have to hunt for it a bit...
First things to check as usual, rotary fittings.
 
I also had to use different tubing for the fill port connection as the black stuff wouldn't bend enough:

Oh well, still looks fairly nice 

So the radiators came with two sets of longs screws, some too long for the fans+panel, and some that were too short.
I don't think these radiators are intended to be installed like this (mounted to a panel through the fans). But I liked the way it looks, and I managed to make it work in the end:

This also gives the top fans a little more clearance, which can only be a good thing.
The current status of the build:

 

I'd be a little worried about those fittings outside the case.
My last water-cooled build with soft tubing (aside from the one I'm working on now), was five years ago, so maybe things have changed since then, but every leak I have ever experienced was the result of a rotary fitting being put under some sort of tension.
As a rule, I avoid using them on soft tubing for this reason, too easy to accidentally tension them and cause problems.
Then again, it's outside the case so I guess even if it does leak it shouldn't be too big a problem!
Just out of interest, what order does coolant go through the radiators? I've never stacked radiators, but I've always imagined that passing the coolant through the "outer" one first (or whichever is receiving exhaust air from another radiator) ought to lead to better heat dissipation. Rate of energy dissipation being proportional to temperature differential and all.

Here you go 

Here you go 

I last replaced my rig in 2015. It was a water-cooled ncase-m1 build with a 4790k and a gtx970. She was a beautiful machine, but she's getting a little long in the tooth now.
Anyway, about a week ago, I found a good deal on a used 3960x and trx40 motherboard. I decided to place a bid, and if I got the parts at a decent price I'd go forward with the build.
I'm here so you can probably guess what happened. Ended up getting the board and CPU for £1100!
 
The planned specs are as follows:
3960x Gigabyte trx40 aorus master 64GB 3600mhz memory 500GB sabrent rocket pcie4.0 ssd Fractal design s2 meshify (because I did another build here on the forum in a fractal case and I thought it was pretty solid) MSI gtx 1080 gaming-X (as I already have it, and I don't really need anything faster) Custom loop! (because building a PC without one is no fun at all) The plan is to update the build as it unfolds over the next few days, adding posts to the thread and updating the OP as things progress.
 
[Sunday 20/09/2020]
I have some of the parts in hand already and the rest should arrive tomorrow.

I don't actually have any ddr4 on hand (all my systems are too old for that) so I won't know until tomorrow if the secondhand CPU/Motherboard I have been sold are any good! 🤞
 
[Later that same evening...]
Well that didn't take long.
The first bit of drama I've run into is that the CPU came without the orange carrier tray or shmansy AMD torque wrench. This is all I got:

Quick google reveals that it's a t20 driver with a torque of 1.5 newton-metres. It looks like the carrier frame isn't actually load-bearing, and is just there to make inserting/removing the processor safer (less likely to accidentally break the socket). Also the CPU has notches in it, like any other processor, which engage with the socket when it's inserted. So it looks like the carrier frame isn't responsible for aligning the pins either.
I managed to get it installed with this thing, which I originally bought for installing disk breaks on my mountain bike:

It's pretty crude, but at least I know all the screws should be roughly the same tightness (and at least somewhere close to 1.5NM).
The board and CPU after a little cleaning:

On another note, the motherboard doesn't seem to have been very well taken care of. There are some missing screws, three for the backplate and another for the first m.2 slot. Hopefully I can give it a better home that it had previously, tsk tsk.
That being said, I'm even more apprehensive about turning the thing on now...
 
[Monday 21/09/2020]
Did a post test (without cooling), and all was well. A weight off my mind for sure.
Time to get this show on the road:

 
P.S. Thanks ocuk, I love it when my harribo comes with free watercooling parts 
 
So the radiators came with two sets of longs screws, some too long for the fans+panel, and some that were too short.
I don't think these radiators are intended to be installed like this (mounted to a panel through the fans). But I liked the way it looks, and I managed to make it work in the end:

This also gives the top fans a little more clearance, which can only be a good thing.
The current status of the build:

 
[Tuesday 21/09/2020]
I was up working up until about 3 in the morning last night working on the build, this is how it looks now:

Unfortunately, it doesn't hold air. Worse still, it's a relatively slow leak which means I'm going to have to hunt for it a bit...
First things to check as usual, rotary fittings.
 
I had to use different tubing for the fill port connection as the black stuff wouldn't bend enough:

Oh well, still looks fairly nice
 
[Tuesday evening]
So I found the leak, it was the right angle fitting at the bottom of the pump. I replaced it with a clear tube and put the ball valve at the end:

And on the back:

The tube is old and a little manky, but it's out of sight so I'm not too bothered. There aren't any clamps, but these barbs are actually meant for larger tubes, so they'll hold. Certainly took some doing to get them on there.
Time for a leak test:

Wish me luck 😬
 
[A bit later]
Disaster has struck.
 
The filling of the loop went off without a hitch, no problems there. But while I was bleeding it, I got the bright idea to connect the top fans to the external power supply I was using to power the pump. No particular reason, just wanted to see them spin, maybe get a feel for the amount of airflow. The fan controller though was connected to the motherboard with a 12v and ground via a system fan header, so I can only assume the board saw 12v and a path to ground and promptly tried to start up. There was a pop, some magic smoke escaped from somewhere near the system fan header, and that was that.
I have been building systems for almost ten years and I have made plenty of mistakes, but this is the first time I've killed a motherboard 😪. As this is my fault, I consider myself morally obliged to eat the cost of a replacement board.
All in all, a bad day.
I have tested as many other components as I can, PSU, memory, SSD, and they are all fine which is a good sign. The GPU wasn't installed at the time either so that's fine too. But the big ticket item is the CPU. I have no way to test it, and if it's dead, then my day will get a lot worse.
 
Moral of the story:
Be very careful when using an external power supply to power components in your PC. Make sure that any components you connect it to are completely disconnected from the rest of the system. If they are not, you are in for a bad time.
 
[Wednesday 23/09/2020]
I have taken it out of the system now and found the borked chip:

The serial number is 3947s934gb, made by nuvoton. There are several of them on the board, they appear just to be fan controllers.
If that's the only damage, it might be repairable 🤔
 
[Thursday 24/09/2020]
New board has arrived. This evening I'll get it installed, hopefully I can polish off the build without killing this one.

Even at the cost of a new motherboard, I'm actually still £150 below retail price on the motherboard and processor. Fingers crossed the CPU isn't damaged.
 
[Later that evening]
The system works now, but there are more issues. 
 
The first is that the fans have very little clearance on their front face and scrape against the metal on the radiator and case at higher RPMs. So I'm going to have to remount them with the spacers on the other side. I have done this for the front radiator, but the top radiator will be a little more difficult. I may have to drill the threads out of the nuts I was using as spacers.
 
The other issue is the GPU. The machine simply refuses to post with it installed.
I have tried other GPUs (an rx550, and a gtx680) and they work fine.
I have tried the 1080 in other systems, and it works fine. I even tried it in an am2+ board from 2009 and it worked perfectly!
I have measured the pcie power cables with a voltmeter to check that the card is getting power. It is.
I have tried updating the motherboard bios.
I tried the GPU with every past bios that has ever existed for it. No luck.
This is actually a problem that I have had before with this card. Another board a couple years ago, an (also gigabyte) gaz68xp-ud3p also refused to post with the GPU installed. I'm beginning to think this is some sort of weird bios bug that only presents itself with MSI GPUs and gigabyte motherboards. It could also explain why there are so many MSI gaming X cards from this generation on ebay. And why they seem to be cheaper than the others.
Whatever it is, it must be something pretty fundamental to have spanned 9 years of hardware. To top it all off, the post code I get with the card installed (0D) isn't even in the manual! Just fantastic.
 
[Friday 25/09/2020]
So I picked up a replacement card on ebay and it seems to be working properly. The plan is to sell the old one to cover the cost.
The evga card works.
 
I have seen many reports of 10 series cards not posting in various motherboards and a disproportionate number of those issues seem to be with MSI cards. I pretty sure they just guffed up the bios on these cards somehow. Oh well, I suppose I'll just include a note and a return postage label with the card when I sell it.
 
Here's the system now:

Not without some more issues though (why not?).
One of the things I wanted was fan control via coolant temperature. Fortunately the board supports this with a couple of headers for 10k thermistors. For reasons that defy all logic and sense though, certain fans can only be controlled by certain sensors. The sensor that suited my needs however, was sandwiched between the edge of a usb2 header and the bottom-most PCIe slot.
I ended up having to solder some new leads on that would fit in the gap:

Can't say I was thrilled about soldering this close to by far the most valuable computer I have ever owned, but hey ho. It had to be done. I'm sure the cardboard will protect it from the 250 centigrade molten metal 😆.

Time to get an OS installed 😉:

6-pin connections? Do you mean the fan connectors? Install on the 4 pin molex? I have no idea what you are trying to ask here. Are you trying to install 4 pin fans on the 6 pin headers, if so pinouts can be found earlier in the thread.
The plaque? Again, I don't know what you mean. I assume you're trying to connect the front panel header (power button etc)? If so the pinout can be found earlier in the thread too.
That's an indicator light, it can be turned on or off in software and is there to identify the server when it's installed in a rack, it's not a power button.

Massive necro incoming, but I figured I'd leave the solution here anyway for anyone else that comes along.
I too ended up running into the bios problem, then solved it and promptly forgot about this thread (my bad).
Anyway, the dl180/se316m/x1600 are actually all the same server (more or less), with the same bios. The bios update comes packaged as a utility that runs from within windows, it's a bit weird, but it does actually work.
You can find the updater on the hpe website here.
 
P.S. There was some confusion for me early on in this project as to which board is which, this should clarify:
dl180/se316m/se326m/se1220/x1600(?):
Some of these have the integrated lights out connector (rj45) built into the board, others have a small daughter board that plugs into the board separately (see the small plug next to the button midway up the right side of the board in this picture). I tried briefly to use it, but it's a nightmare. It's flakey as hell, I couldn't get it to open in anything but IE, and a good chunk of the functionality is locked behind a license. So if you ask me, it's no great loss. I ended up using ordinary wake-on-lan to power up my nodes.
 
dl160 (and probably a slew of other names too...):
I have no experience with this board, though greenie214 (from earlier in this thread) does.
 
P.P.S. The cluster, janky though it may be, is very much still kicking!
It has been (and continues to be) an interesting project:
 

Massive necro incoming, but I figured I'd leave the solution here anyway for anyone else that comes along.
I too ended up running into the bios problem, then solved it and promptly forgot about this thread (my bad).
Anyway, the dl180/se316m/x1600 are actually all the same server (more or less), with the same bios. The bios update comes packaged as a utility that runs from within windows, it's a bit weird, but it does actually work.
You can find the updater on the hpe website here.
 
P.S. There was some confusion for me early on in this project as to which board is which, this should clarify:
dl180/se316m/se326m/se1220/x1600(?):
Some of these have the integrated lights out connector (rj45) built into the board, others have a small daughter board that plugs into the board separately (see the small plug next to the button midway up the right side of the board in this picture). I tried briefly to use it, but it's a nightmare. It's flakey as hell, I couldn't get it to open in anything but IE, and a good chunk of the functionality is locked behind a license. So if you ask me, it's no great loss. I ended up using ordinary wake-on-lan to power up my nodes.
 
dl160 (and probably a slew of other names too...):
I have no experience with this board, though greenie214 (from earlier in this thread) does.
 
P.P.S. The cluster, janky though it may be, is very much still kicking!
It has been (and continues to be) an interesting project:
 

Massive necro incoming, but I figured I'd leave the solution here anyway for anyone else that comes along.
I too ended up running into the bios problem, then solved it and promptly forgot about this thread (my bad).
Anyway, the dl180/se316m/x1600 are actually all the same server (more or less), with the same bios. The bios update comes packaged as a utility that runs from within windows, it's a bit weird, but it does actually work.
You can find the updater on the hpe website here.
 
P.S. There was some confusion for me early on in this project as to which board is which, this should clarify:
dl180/se316m/se326m/se1220/x1600(?):
Some of these have the integrated lights out connector (rj45) built into the board, others have a small daughter board that plugs into the board separately (see the small plug next to the button midway up the right side of the board in this picture). I tried briefly to use it, but it's a nightmare. It's flakey as hell, I couldn't get it to open in anything but IE, and a good chunk of the functionality is locked behind a license. So if you ask me, it's no great loss. I ended up using ordinary wake-on-lan to power up my nodes.
 
dl160 (and probably a slew of other names too...):
I have no experience with this board, though greenie214 (from earlier in this thread) does.
 
P.P.S. The cluster, janky though it may be, is very much still kicking!
It has been (and continues to be) an interesting project:
 

Problem solve by getting another 8gb 2400mhz ram stick. Before: 1x8gb 2400mhz. Now: 2x8gb 2400mhz. Dual-Channel and not the amount of ram did the trick. 
ALWAYS USE DUAL CHANNEL FOR GAMING. Thank again guys.
 
Problem Solve: