SOLVED My PC wont boot after a PSU failure and replacing almost everything

[AveryD]

I’ve got problems. I'm running a watercooled Ryzen 5 5700x, Geforce RTX 3070 Ti, 4-DIMMs of Kingston Hyper X 3200 DDR4, Asus ROG Strix B550-F MB and a Corsair RM850e PSU. Before this, I was running an MSI Radeon 5700XT GPU and a Corsair 650 PSU. I upgraded the Radeon to a Geforce RTX 3070 Ti. The computer was working and I was playing a game for about 30 minutes when the PSU failed. A pop, grind and some burning scent was present. The PSU was the only thing that smelt of burning electronics. I consulted an IT guy I work with who figured that since the GPU required 750w minimum in the PSU, the PSU is all that needs replacing, since the PSU should protect everything else when it pops. I replaced the PSU to the Corsair RM850X, but all that would turn on is the one LED strip at the top left of the B550-F when the PSU switch was turned on, but the computer would not boot, regardless of what I tried (paperclip method, etc). 
Then we figured that the MB must've been fried too, so I replaced that, same thing as before. LED but no boot. So on the off chance the 850X was defective out of the box, I got the RM850e which is in there now. That still wasn't working.
The next step was to see if the PC would boot with the GPU removed. I removed the GPU first and the PC booted right up, HORRAY!! The original PSU must've fried the GPU when it went. So I replaced the GPU, it’s another 3070 Ti, and it’s the same damn result. Won’t boot. The computer only boots when the GPU is unplugged. If I plug the GPU in when the PC it booted, it shuts off. I also tried this with the old MSI GPU, same thing. 
Please help, I have absolutely no idea what to do anymore. Thanks

 

 

SOLVED 

 

One of the power cables that came with the original PSU that I ended up keeping for the GPU was defective.
 

Quite the expensive thing to figure out, who’d think the problem came in with the replacement parts 

[An0maly_76]

Sounds like the board is damaged. I've had a PSU fail and nuke an entire system before.

 

What may have happened here... PSU damages board, damaged board damages new PSU, new damaged PSU damages new board.

 

But you might also try a G variant to check the BIOS to see if something isn't right there.

[Hinjima]

I am following this thread because I am actually extremely curious about the outcome and tips people recommend.  If by any chance I can hop in with some insight I will of course do so, however my electricity knowledge is limited. I wish you the best of luck, what an awful situation.

[AveryD]

16 hours ago, An0maly_76 said:

Sounds like the board is damaged. I've had a PSU fail and nuke an entire system before.

 

What may have happened here... PSU damages board, damaged board damages new PSU, new damaged PSU damages new board.

 

But you might also try a G variant to check the BIOS to see if something isn't right there.

If the board is fried then why does it boot up with the GPU unplugged? 
 

Also, what’s a G variant?

[An0maly_76]

5 minutes ago, AveryD said:

If the board is fried then why does it boot up with the GPU unplugged? 
 

Also, what’s a G variant?

 

I said damaged, not fried. Boards can be damaged and still partially function. Apparently something isn't right in the PCIe. Ryzen G-variants incorporate integrated graphics that display through the motherboard's output. 5600 vs 5600G vs a 5600X, for example. The X / non-X/G would not have this, the G's do.

 

Short of something wrong with the board, the BIOS may have defaulted to iGPU only, which would explain why it won't boot with a GPU card. Hence my suggestion of using a G-variant to check the BIOS using the board's display output.

[AveryD]

20 hours ago, An0maly_76 said:

 

I said damaged, not fried. Boards can be damaged and still partially function. Apparently something isn't right in the PCIe. Ryzen G-variants incorporate integrated graphics that display through the motherboard's output. 5600 vs 5600G vs a 5600X, for example. The X / non-X/G would not have this, the G's do.

 

Short of something wrong with the board, the BIOS may have defaulted to iGPU only, which would explain why it won't boot with a GPU card. Hence my suggestion of using a G-variant to check the BIOS using the board's display output.

So I’d need to get a CPU that’s a G version? Is there anyway I can change from the iGPU in the bios w/o a different CPU?

[An0maly_76]

1 hour ago, AveryD said:

So I’d need to get a CPU that’s a G version? Is there anyway I can change from the iGPU in the bios w/o a different CPU?

You could try resetting the CMOS, which should default it to auto-select. It should then switch to the GPU and POST normally, but I've seen RAM cause no-video POSTs also. And it's certainly possible the PSU failure could have corrupted the BIOS and/or damaged the RAM / board.

 

So let's recap. PSU failed. PSU replaced. No boot with GPU. Motherboard and GPU replaced. Still no boot with GPU. Without video, are you even sure it's POSTing?

Edited February 19, 2023 by An0maly_76
Revised, more info

[AveryD]

2 hours ago, An0maly_76 said:

You could try resetting the CMOS, which should default it to auto-select. It should then switch to the GPU and POST normally, but I've seen RAM cause no-video POSTs also. And it's certainly possible the PSU failure could have corrupted the BIOS and/or damaged the RAM / board.

 

So let's recap. PSU failed. PSU replaced. No boot with GPU. Motherboard and GPU replaced. Still no boot with GPU. Without video, are you even sure it's POSTing?

 No I cant tell if its posting when it boots up w/o the GPU. 
 

From what I gather it’s possible I need a new MB and RAM. Is there a way I can confirm this before buying these items?

[An0maly_76]

1 hour ago, AveryD said:

 No I cant tell if its posting when it boots up w/o the GPU. 
 

From what I gather it’s possible I need a new MB and RAM. Is there a way I can confirm this before buying these items?

Checking your board manufacturer's compatibility list will tell you whether a given RAM SKU (part #) is recommended. RAM can work, but still not be recommended due to instability issues, and I have seen no video on start like this with no confirmation of whether it was a failed POST or a complete boot to Windows with no video.

 

I would have a local shop test the board with an iGPU and a different GPU before condemning it. They can also test the RAM, which will give you independent confirmation. However, my problem DIMMs tested fine in memtest86, it was just the board and CPU that did not like them. I have also seen proprietary prebuilt PCs with mobos that only supported certain video cards. Lenovo is known for this, as are some others.

[AveryD]

2 hours ago, An0maly_76 said:

Checking your board manufacturer's compatibility list will tell you whether a given RAM SKU (part #) is recommended. RAM can work, but still not be recommended due to instability issues, and I have seen no video on start like this with no confirmation of whether it was a failed POST or a complete boot to Windows with no video.

 

I would have a local shop test the board with an iGPU and a different GPU before condemning it. They can also test the RAM, which will give you independent confirmation. However, my problem DIMMs tested fine in memtest86, it was just the board and CPU that did not like them. I have also seen proprietary prebuilt PCs with mobos that only supported certain video cards. Lenovo is known for this, as are some others.

I’ll look into this, thanks

[AveryD]

SOLVED 

 

One of the power cables that came with the original PSU that I ended up keeping for the GPU was defective.
 

Quite the expensive thing to figure out, who’d think the problem came in with the replacement parts