Question PC died and the EZ Debug VGA light is on. I tried a bunch of things, no clue what's wrong ?

[thenevernow]

Hi everyone, here's my sad story. There was a storm the other day and it did some damage to my PC, but 4 days and a lot of frustration later, I still can't figure out what's wrong.

Setup:
Motherboard: MSI MPG B550 Gaming Plus
CPU: AMD Ryzen 5 5600x
GPU: Sapphire Radeon 7900 GRE
RAM: 32GB (4x8GB) KINGSTON FURY Renegade DDR4-3200
PSU: be quiet! Pure Power 12 M 750 Watt (replaced with a Corsair Rm850X, see below)
Storage: WD Black SSD SN770 M.2 2280
Case (just in... case): Fractal Design Pop Silent Black Solid

The storm hit, the computer failed and turned off. I understand the damage could be limited to a cable or the whole thing could be fried, I accept that, stay with me.
The storm is over, the computer won't turn back on, I open it up and the EZ Debug light is on (solid white). Oh no, my GPU is dead! But I have an older GPU around, so before succumbing to despair I swap them and nothing changes. Ok, so maybe it's not the CPU. Other parts from my other PC are not swappable (too old and Intel-based), so I need fresh components.

First, I got a new MB, same as the old one. Exact same behaviour. Then the CPU (same one), still no luck. I thought "Ok, it's the PSU" and got a new one (different from the old one, see Setup above). Nothing.

Things I HAVEN'T tried yet:
- replace the RAM. I did however swap around the 4 modules I have. I can't be sure but they don't seem to be the problem. The EZ Debug RAM light never turns on when at least one module is installed.
- remove the MB from the case
- sacrifices to the Great Old Ones

Things I HAVE tried:
- verifying that the monitor the PC is connected to works fine
- replacing the HDMI cable
- using a DVI cable (with my older GPU) instead of HDMI
- replacing the power cable
- using a different wall power outlet
- booting without a monitor attached and with one
- removing the M.2 SSD or leaving it in place
- removing all MB-case connectors (fans, USB, audio). I even tested with no CPU fan connected but briefly, for obvious reasons
- checked that my older GPU works fine - it does. I know my CPU doesn't do video so I need an actual GPU in place. Put it back in the old system, all good
- tried the other PCI-E slot for the GPU
- cleared the CMOS (but probably irrelevant as I am now using a brand new MB)
- read all relevant conversation about EZ debug I could find here and elsewhere (nothing actually helpful, what I gathered is that the VGA light is supposed to also cover PCI-E and M.2, but is seems that people had it on and the issue was with the CPU or the MB itself or something else)

I hope I didn't forget anything. I know I still have a couple of things to try (replacing the RAM, mainly), but if anyone has any clue what's going on and what I should do, I'd be infinitely thankful.

Also, a couple of specific questions:

- is my PC (my MB, really) boot (to a BIOS error screen, at least) without a storage device attached?
I'm assuming yes, but I could always be wrong
- same question, no monitor connected. Same assumption as above

Thanks in advance! 🙏

 

[Lutfij]

Welcome to the forums, newcomer!

You might want to see if you can perform a BIOS flash, using the BIOS Flash button on the rear of your motherboard, in tandem with the info given in your motherboard manual;
https://download.msi.com/archive/mnu_exe/mb/MPGB550GAMINGPLUS_EN.pdf
Page 51. See if that helps revive your system.

If you were tethered to the internet using your Ethernet port, then it's possible your board and everything connected to it was fried. You will need to cross-reference/swap/drop all your components onto known working parts and vice versa to rule out what parts conked out. I'm assuming everything and over time you'll see more and more parts fail or exhibit odd behaviors. You should consider sourcing(borrow, not buy) parts to help you in your troubleshooting process.

 

[thenevernow]

Thanks for your reply, however I suspect you haven't really read my post. With the exception of RAM, which I am replacing today, I have already swapped out all components, apart from the case. In particular, the motherboard is a brand new replacement.

 

[thenevernow]

In any case, I just replaced the RAM with a brand new module (yes, the MB supports a single module configuration) and flashed the most recent BIOS via USB. Nothing changed.
At the moment the only component that was present in the build when the problem occurred is the case. I'm stumped.

 

[thenevernow]

Last update: I took everything out of the case and propped it on a cardboard box. VGA light still on, no boot. Right now there is NO compoment overlap with the build where the original problem occurred.

 

[Richj444]

Last update: I took everything out of the case and propped it on a cardboard box. VGA light still on, no boot. Right now there is NO compoment overlap with the build where the original problem occurred.

What old gpu did you try? Did you try your new gpu in the old system?

 

[thenevernow]

What old gpu did you try? Did you try your new gpu in the old system?

Thanks for your reply. My old GPU is a PowerColor Red Dragon Radeon RX 480.
To be clear, there's no actual "new" GPU. There's my current one, the 7900 GRE, and my older one, the RX 480. I didn't get a brand new replacement for the 7900 since, unlike other components, I had the RX 480 to test.

 

[Richj444]

Thanks for your reply. My old GPU is a PowerColor Red Dragon Radeon RX 480.
To be clear, there's no actual "new" GPU. There's my current one, the 7900 GRE, and my older one, the RX 480. I didn't get a brand new replacement for the 7900 since, unlike other components, I had the RX 480 to test.

I'm wondering about the 480 and the old system it was in. Is the old system in CSM/Legacy mode and your new system in UEFI mode by chance? I've heard of issues with older cards not working with EUFI. If, and I'm not saying for sure it is, but if that's the issue then swapping the 480 into your system didn't prove anything. Try your 7900 in the old system. If it works there, then the 7900 isn't your problem. But I'm pretty suspicious that your 7900 is defective and that's what the vga debug light is telling you. It would be really great if you could borrow a loaner, modern GPU to test in your system.

 

[thenevernow]

I'm wondering about the 480 and the old system it was in. Is the old system in CSM/Legacy mode and your new system in UEFI mode by chance? I've heard of issues with older cards not working with EUFI. If, and I'm not saying for sure it is, but if that's the issue then swapping the 480 into your system didn't prove anything. Try your 7900 in the old system. If it works there, then the 7900 isn't your problem. But I'm pretty suspicious that your 7900 is defective and that's what the vga debug light is telling you. It would be really great if you could borrow a loaner, modern GPU to test in your system.

Do you think the RX 480 is old enough that it might not work with UEFI? Honestly I don't know for sure, but I do see your point about not proving anything.
Unfortunately I can't directly test the 7900 in my old system because it won't physically fit and I'm not sure it has 2x8pin power outputs, but I could do a Frankenstein and run a caseless old system with a new PSU and the new GPU.
'Finally, I don't have many options in terms of borrowing stuff. I gave my 7900 to an acquaintance to test, but it wouldn't fit his case and I'm not in the position of asking him to tear apart his system for me.
All this said, it's over bedtime here now, but I think I'll try the Frankenstein thing in the morning. Thanks.

 

[Richj444]

Do you think the RX 480 is old enough that it might not work with UEFI? Honestly I don't know for sure, but I do see your point about not proving anything.
Unfortunately I can't directly test the 7900 in my old system because it won't physically fit and I'm not sure it has 2x8pin power outputs, but I could do a Frankenstein and run a caseless old system with a new PSU and the new GPU.
'Finally, I don't have many options in terms of borrowing stuff. I gave my 7900 to an acquaintance to test, but it wouldn't fit his case and I'm not in the position of asking him to tear apart his system for me.
All this said, it's over bedtime here now, but I think I'll try the Frankenstein thing in the morning. Thanks.

Without doing more research I'm not positive about the 480, but it's definitely possible that's the issue. Good luck with the Frankenstein thing. You might also be able to talk a local shop into popping in a 7900 or equivalent into your system, or popping your 7900 into their system as a test. Hopefully that wouldn't be too costly.

 

[thenevernow]

Without doing more research I'm not positive about the 480, but it's definitely possible that's the issue. Good luck with the Frankenstein thing. You might also be able to talk a local shop into popping in a 7900 or equivalent into your system, or popping your 7900 into their system as a test. Hopefully that wouldn't be too costly.

Yeah, at this point I'm open to the shop option, but it's peak summertime here and most non-essential businesses are closed, so I'll have to wait for that.

 

[thenevernow]

In yesterday's enthusiasm, I forgot that my 7900 is with my acquaintance and I'm unable to collect it immediately, so I can't do any more tests with it now. I'll update the thread when I have news of any kind.

 

[thenevernow]

For anyone following this, here are the latest, rather perplexing, developments.

I bit the bullet and got a replacement GPU (same as the old one, Radeon 7900 GRE). Unfortunately, the PC still wouldn't boot (same as always, EZ Debug VGA LED on).

Out of options and out of hope, I checked the two computer shops I know and kinda trust and luckily one of them had reopened after their holiday period, so I paid them a visit and told them what happened and all the things I have already tried. Here's what we found out:

• the old GPU is dead (tested in a rig of their own)
• my PC will boot with a GPU that doesn't need external power (a spare one they have around for testing)
• the new GPU is fine (as expected, it was fresh out of the box)
• my PC still won't boot with my new GPU

The second point in my list suggests the PSU can't do its job properly, although it can do it somehow. It was about closing time, so I left my PC with them for more in-depth testing, they should call me some time next week.

 

[thenevernow]

Well, the shop guys took it apart completely, put it back together and... it just worked. No one is quite sure why. So it seems only the GPU was actually dead after all.

 

[DaleH]

Well, the shop guys took it apart completely, put it back together and... it just worked. No one is quite sure why. So it seems only the GPU was actually dead after all.

"no one is quite sure why" : this is not uncommon in troubleshooting, especially if more that one person is involved.

 

[thenevernow]

True. They say that maybe the power cable from the PSU to the GPU was not plugged all the way and it's certainly possible, but I'm still a bit puzzled by the whole story.