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Dell Optiplex 790 power switch?

I just posted in another optiplex thread in this forum. My board arrived today and I got everything working so far. I have the same "problems" as you but I think I can live with them. I can confirm your statement on the 2 power pins; works fine for me, too. 

 

I installed 8gb of corsair xms3 ram onto it and an intel i5-2500k. Runs perfectly well on this Dell D28YY.

 

The only thing I will have to solve in the next days is the graphics card. I can't install a 2-slot card because the 24-pin power connector is in the way. I just bought a PCIe riser which will hopefully solve this problem. I will write an update as soon as it arrives (will be around saturday I guess).

 

For other people interested in this topic I will just link the other thread I posted in: 

 

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On 8/10/2017 at 11:21 PM, madtrigger said:

I just posted in another optiplex thread in this forum. My board arrived today and I got everything working so far. I have the same "problems" as you but I think I can live with them. I can confirm your statement on the 2 power pins; works fine for me, too. 

 

I installed 8gb of corsair xms3 ram onto it and an intel i5-2500k. Runs perfectly well on this Dell D28YY.

 

The only thing I will have to solve in the next days is the graphics card. I can't install a 2-slot card because the 24-pin power connector is in the way. I just bought a PCIe riser which will hopefully solve this problem. I will write an update as soon as it arrives (will be around saturday I guess).

 

For other people interested in this topic I will just link the other thread I posted in: 

 

Sweet as! Glad to hear everything is working :P

Got some generic ass ram working, 2x2gb (plex server) and my i3-2130.

Sucks about the gpu, are you planning to game on it? And the board seems pretty tough as well.

Yours in a case? I've built a wooden chassis for mine but ordered some power pins/reset pins and leds to mount on it, are the front two pins power? (i switch the psu to switch it on)

 

EDIT: WOO, also managed to disable the annoying messages on boot. So now I can hide this away in a cupboard, and teamview into it ;) 

Specs

CPU: i7-6700k @ 4.4GHz

GPU2 x Gigabyte GTX 980 G1 Gaming SLI
RAMG.Skill Ripjaws 4 x 8GB @ 2400MHz (32GB)
MOBOASUS Z270-AR PRIME
CASE: Corsair 750D
COOLINGCorsair H100 v2, SP120 & AF120 fans
PSUCorsair TX850M

STORAGE1 x 2TB HDD, 3 x 1TB HDD 1 x M.2 Samsung 960 EVO 250GB

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17 hours ago, nixtone said:

Sweet as! Glad to hear everything is working :P

Got some generic ass ram working, 2x2gb (plex server) and my i3-2130.

Sucks about the gpu, are you planning to game on it? And the board seems pretty tough as well.

Yours in a case? I've built a wooden chassis for mine but ordered some power pins/reset pins and leds to mount on it, are the front two pins power? (i switch the psu to switch it on)

 

EDIT: WOO, also managed to disable the annoying messages on boot. So now I can hide this away in a cupboard, and teamview into it ;) 

I wanna game on it, yes. The PCIe riser should arrive today or monday. I will have to build a little mount to hold it in place though. I am using a default atx case with a regular 2-pin power switch connection. I had to destroy the plastic socked but it works fine. Do you use a single-slot graphics card?

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25 minutes ago, madtrigger said:

I wanna game on it, yes. The PCIe riser should arrive today or monday. I will have to build a little mount to hold it in place though. I am using a default atx case with a regular 2-pin power switch connection. I had to destroy the plastic socked but it works fine. Do you use a single-slot graphics card?

I've got a gt 730 for it atm but as I've built it as a server I'm running off integrated graphics which I won't need due to remote desktop.

Do you happen to know which ones are LED pins? 

1 2 3 

1 2 3 4

 

1 and 1 is power? 2 and 2 must be reset and 33 hdd led and 4 status led? no idea lol

Specs

CPU: i7-6700k @ 4.4GHz

GPU2 x Gigabyte GTX 980 G1 Gaming SLI
RAMG.Skill Ripjaws 4 x 8GB @ 2400MHz (32GB)
MOBOASUS Z270-AR PRIME
CASE: Corsair 750D
COOLINGCorsair H100 v2, SP120 & AF120 fans
PSUCorsair TX850M

STORAGE1 x 2TB HDD, 3 x 1TB HDD 1 x M.2 Samsung 960 EVO 250GB

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I think the two pins in the middle are for the led, since the outer two are for the power switch.

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How did you destroy the plastic shrouding? :P

Specs

CPU: i7-6700k @ 4.4GHz

GPU2 x Gigabyte GTX 980 G1 Gaming SLI
RAMG.Skill Ripjaws 4 x 8GB @ 2400MHz (32GB)
MOBOASUS Z270-AR PRIME
CASE: Corsair 750D
COOLINGCorsair H100 v2, SP120 & AF120 fans
PSUCorsair TX850M

STORAGE1 x 2TB HDD, 3 x 1TB HDD 1 x M.2 Samsung 960 EVO 250GB

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4 hours ago, nixtone said:

How did you destroy the plastic shrouding? :P

With brute force! ;) The shrouding is a bit smaller than a default 2-Pin-Connector, therefore I had to kinda break it to make it fit on the pins.


Btw: my PCIe riser arrived today. I just installed the graphics card (GTX 560), and everything works perfectly fine. And when you take a look at the photo ... yes, I screwed a piece of wood into my pc. It was the easiest way to attach the riser. :D 

IMG_20170817_123647.jpg

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3 hours ago, madtrigger said:

With brute force! ;) The shrouding is a bit smaller than a default 2-Pin-Connector, therefore I had to kinda break it to make it fit on the pins.


Btw: my PCIe riser arrived today. I just installed the graphics card (GTX 560), and everything works perfectly fine. And when you take a look at the photo ... yes, I screwed a piece of wood into my pc. It was the easiest way to attach the riser. :D 

IMG_20170817_123647.jpg

Fuck that's nice as, and lmao @ the wood

I filed down my 2 pin connector and squeezed it in, works for now :P

PCIE riser affect performance?

Specs

CPU: i7-6700k @ 4.4GHz

GPU2 x Gigabyte GTX 980 G1 Gaming SLI
RAMG.Skill Ripjaws 4 x 8GB @ 2400MHz (32GB)
MOBOASUS Z270-AR PRIME
CASE: Corsair 750D
COOLINGCorsair H100 v2, SP120 & AF120 fans
PSUCorsair TX850M

STORAGE1 x 2TB HDD, 3 x 1TB HDD 1 x M.2 Samsung 960 EVO 250GB

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6 hours ago, nixtone said:

Fuck that's nice as, and lmao @ the wood

I filed down my 2 pin connector and squeezed it in, works for now :P

PCIE riser affect performance?

Unfortunately I can't tell, if it is worse than before because I have never benchmarked this system. But it doesn't feel any slower in games, which should be a sign, that the loss of performance is, if at all, marginal.

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  • 5 months later...

@nixtone can you explain me how to u solve the power sw problem? i have a new case with a 2 pin power sw and the motherboard its from a DELL Optiplex 790 and have that power sw wint 5 pins. Can you help me out? Thanks

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  • 1 month later...

I can't even tell you how glad I am that this popped up.  I JUST bought a 790 on eBay (there is a 15% off everything sale with the promo code PREPSPRINT until 10PM Central) and I'm planning on swapping the case when it arrives.

Make sure to quote or tag me (@JoostinOnline) or I won't see your response!

PSU Tier List  |  The Real Reason Delidding Improves Temperatures"2K" does not mean 2560×1440 

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You can control the fans with speed fan. Also you can use custom pwm 4 pin fans after swapping two wires. I have a thread on modding a 790 mini-tower that might interest you.

Black Knight-

Ryzen 5 5600, GIGABYTE B550M DS3H, 16Gb Corsair Vengeance LPX 3000mhz, Asrock RX 6800 XT Phantom Gaming,

Seasonic Focus GM 750, Samsung EVO 860 EVO SSD M.2, Intel 660p Series M.2 2280 1TB PCIe NVMe, Linux Mint 20.2 Cinnamon

 

Daughter's Rig;

MSI B450 A Pro, Ryzen 5 3600x, 16GB Corsair Vengeance LPX 3000mhz, Silicon Power A55 512GB SSD, Gigabyte RX 5700 Gaming OC, Corsair CX430

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From my experience doing this...

 

for power switch connector you can get an adapter cable from moddiy.com for around $5 just get that makes it easier than DIY re-wiring

 

for sys_fan connector either leave original fan plugged in somewhere or get a dell->pwm adapter from moddiy.com for about $5... easy

 

for cpu_fan I would just use stock cooler as they’re non-k chips and won’t need extra cooling. If you insist on changing it use a moddiy.com adapter.

 

now... front panel...

if you leave it unplugged it will error on POST. There is no adapter on the market. I gave up and lived without he front panel audio+usb2 ports.

the hdd-led is on this connector and that’s easy to just crimp onto a standard 2pin plug and get working. In order to have the POST error disappear you need to bridge the 2 black/ground wires from the USB bundle so it thinks he front panel is plugged in.

 

i have a wiring diagram I made somewhere if you search for old posts from me about HDAUDIO connectors I made before I gave up :)

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  • 10 months later...

 

I've been searching for a few hours now on this particular board model. I'm trying to make a test bench of sorts without a case. I have a 430w PSU, 2x8GB of samsung ddr3 240pin, GTX 660, 128GB SSD, and an i3-2120. I just purchased a dell 790 SFF motherboard only, and from the research I've done it should work. I came across this post and you seem to be knowledgeable about this model and motherboard.. My plan is to short the pins to start up the machine the first time, and then have it boot on power for the future. Will this work? Also, I have seen conflicting reports about the GTX 660 which is two slots wide. Will it fit on top of this motherboard without a case or do I need a PCIE riser/adapter?

 

Thanks for any help

 

 

Edit: since it seems easy enough to put this in a standard case, I only need some help connecting the front panel of the new case to the motherboard. 

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Ok so regarding the PCI slots. the 660 will fit and work fine, but put it in the slot nearest the CPU as this is the only PCIe3.0 x16 slot. without a case on any size card will fit, the SFF part only matters about the height of the original case. any mATX/ATX aftermarket case will fit the 660 perfectly.

 

shorting the power pins will indeed boot the board, but its a pain to live with. i'd recommend you get a power button adapter from MODDIY to make your life so much easier. personally i made my own with some jumper connectors as i did it before i discovered MODDIY

 

you'll also NEED at least 1 fan adapter for the CPU fan header otherise you cant plug in the CPU fan. i'd also reccomend one for the SYS_FAN header as without it the board will erro on post so you get a "press f1 to continue" prompt

 

expect to get POST errors without the front panel connectors plugged in. you'll want to EITHER  short the ground pins on the front panel connector to make it detect it's plugged in or rig up your own custom adapter to plug in the front panel audio, USB etc.

 

any more questions, just ask. I still have the PC in my house, my son uses it for gaming with a 1050ti stuck in.

 

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10 hours ago, Jay Deah said:

Ok so regarding the PCI slots. the 660 will fit and work fine, but put it in the slot nearest the CPU as this is the only PCIe3.0 x16 slot. without a case on any size card will fit, the SFF part only matters about the height of the original case. any mATX/ATX aftermarket case will fit the 660 perfectly.

 

shorting the power pins will indeed boot the board, but its a pain to live with. i'd recommend you get a power button adapter from MODDIY to make your life so much easier. personally i made my own with some jumper connectors as i did it before i discovered MODDIY

 

you'll also NEED at least 1 fan adapter for the CPU fan header otherise you cant plug in the CPU fan. i'd also reccomend one for the SYS_FAN header as without it the board will erro on post so you get a "press f1 to continue" prompt

 

expect to get POST errors without the front panel connectors plugged in. you'll want to EITHER  short the ground pins on the front panel connector to make it detect it's plugged in or rig up your own custom adapter to plug in the front panel audio, USB etc.

 

any more questions, just ask. I still have the PC in my house, my son uses it for gaming with a 1050ti stuck in.

 

Thanks for the reply! I'm looking at cheap $20 rosewill case to put this in. I bought 1 fan adapter for now for the cpu fan. I do have spare male-to-female jumper cables, I suppose those might work for the power button?

 

Thanks for the info on the POST errors too, we'll see how annoying it is. 

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the issue you have with the power button is that on the motherboard it's a propreitory connector. in my case as i had the original power button i could chop it off at the cable and then solder standard wiring to the old plug. in your case you dont have a plug, and im not sure how easy it will be to make a suitable plug. you could always try it first then order a MODDIY one if you fail?

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On 2/6/2019 at 4:33 PM, Jay Deah said:

the issue you have with the power button is that on the motherboard it's a propreitory connector. in my case as i had the original power button i could chop it off at the cable and then solder standard wiring to the old plug. in your case you dont have a plug, and im not sure how easy it will be to make a suitable plug. you could always try it first then order a MODDIY one if you fail?

Build is in the tower now, pressing F1 doesn't bother me right now. Used two jumper cables for the power button and shaved one down a bit so it would fit in the dell connector on the board. I'm actually running completely fanless thanks to the hyper 212 evo, cpu temps at low 40s during office work / internet browsing. 

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at some point the F1 thing will bother you. for me it took 2 years, but eventually it will :)

 

co-incidentally i'm actually looking at selling this rig now, i gave it to my son but i just picked up a Lenovo Gaming Tower for super-cheap to replace it. I've just ordered a new case for it that will help it sell (no kid wants to buy a "gaming rig" in an old Antec case from the early 2000s) so I've got to transfer the whole thing into a brand new case and i've ordered all the "proper" adapters from MODDIY.com to replace my home-crimped efforts, as otherwise i'd feel guilty selling it to someone :)

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