Question Gigabyte GA-X79-UD7 freezes before post - no hardware changes before this happened

[Adamsan11]

So my gaming PC won't boot. It hangs on the mobo splash screen. It just sits there. No sound, no response to any keys. Safe mode booting is not on the table, this is obv before windows gets going.

The weird bit? I haven't touched the hardware in two years -- I was gaming on it last night.

Below is not my comp, but this is the splash screen I see when it hangs. It just sits right like this.

Can't get into the BIOS settings, can't post, can't do really much of anything. For whatever reason, though none of the other startup commands listed in the splash screen respond, either [post-power up / pre-splash] or [post-splash] ...Ctrl-Alt-Del works to restart at any time.

Specs:

• Mobo = Gigabyte GA-X79-UD7 (original when I built this PC in 2011)
• PSU = CORSAIR|850W CMPSU-850TXV2 R (original when I built in 2011)
• CPU = Intel i7-3930k (original when I built in 2011, not overclocked or anything)
• GPU = Gigabyte GeForce GTX 1070 (a 2017 addition)

Can't stress this enough: There have been no hardware changes in 2 years since the GTX 1070 went in. I was gaming just fine last night. Makes me worry I'm dealing with a component failure somewhere.

Weird note (if this helps): The splash screen above usually fills my 24" monitor like a stretched low-res wallpaper, but in my case since this morning it's now showing itself in what appears to be it's native resolution on center much smaller than the stretched usual version. Leads me to believe that this is GPU related. It's almost like the GPU firmware rev'd without my knowing (is that even possible?), or like it forgot it's PCI Settings (this plagued me in 2017 when I installed the GTX 1070 for the first time due to some legacy PCI settings I had to arm wrestle with but eventually solved).

Here's what I've tried:

1. All of the splash screen button options above. No response to any button presses at any time pre or post splash screen, same outcome. As stated, Ctrl-Alt-Del still works to reboot right back to the same place.
2. In case some critical I-O peripheral had died, I pulled the mouse (USB, guessing that's not it) and the keyboard (PS2 connection, suppose it's possible) and restarted. Same response.
3. Got the case open. No clear signs of bad news: no smoke smell, the GPU didn't have any blown/blackened components or anything like that, all fans were spinning, etc.
4. Killed the power, replaced the mobo flat battery. Same response.
5. Formally did the Mobo jumper move to reset the CMOS. Same response.

Can't pull the GPU as I lack a backup handy -- buried in storage -- and (to my knowledge) there's no integrated graphics already onboard.

Not sure what to do at this point. Theories / Ideas:

• Should I flash / update the BIOS? I'm not sure I've got USB ahead of the primary HDD in the current BIOS boot order, so I think the PC might just drive by a USB Q-flash sort of move and proceed to freezing as before. I don't believe this X79 mobo has the dedicated USB slot QFlash Plus functionality to allow a thumb drive override of the boot order.
• Dig the old GPU out of storage?
• Something has started to fail after all this time and the Mobo is locking up as s result. Think heat sink coming loose, PSU no longer delivering the necessary power, etc. I don't know if I would spot this myself, but I'm willing to take a look if you have any guidance.

Appreciate any ideas you have!

- A

 

[DavidM012]

It is most likely the psu is flaky. You could check the power supply voltages with a multimeter for +/- 5% tolerance being that old it has certainly degraded over time. Why bother? just switch it out with a new one.

Also replace cmos battery with a new cr2032 coin battery. It may have simply drained over time. DO NOT replace cmos battery without checking PSU outputs first. This is critical as a bad psu could also take out the mobo/gpu/entire system. It won't save BIOS settings if no battery.

No need to flash bios no hardware changes have been made since it was last used and won't have any bearing on the gpu.

Equally bad idea if psu is flaky. PSU First before anything your entire system is at risk if you do not sort it straight away.

 

[Adamsan11]

Thanks, David. I have one of those chambered Antec cases that pipes the PSU cords through some passthroughs, so outright swapping the PSU is a labor intensive effort.

Time to pick up a multimeter. Will follow up when I have more to report, thx.

- A

 

[DavidM012]

Make sure that you unplug all the molexes and power connectors from board & drives etc. before testing!

 

[Adamsan11]

Okay, I finally had some time to look at this tonight. Before tearing anything down or checking the PSU voltage, I forgot my mobo had a debug code display.

I had to reboot a few times to capture all 20 or so of them (they whiz by before it locks onto one at freeze), but I think I got them. Cross-referencing against the Gigabyte manual for that mobo and all came from the list under 'Regular Boot'. Nothing from the Error Codes list. The code it locks on to at time of freeze -- and not necessarily the root cause I'm guessing -- is 'b2', which corresponds to 'Legacy Option ROM initialization'.

Googling that is all over the place. If anyone sees that code as a clear tell, please let me know. Otherwise I'll focus on the PSU and possibly dig my old GPU out of storage for a swapout.

Also: Is that extent of cycling through the boot sequence (i.e. the 20 or so debug codes that flew by) a tell that the mobo might actually be in good order and that the problem lies elsewhere? Do mobos 'partially fail', or are they a binary sort of proposition?

- A

 

[Adamsan11]

Update: based on a few folks (with 'b2' debug codes on the mobo) alleging there might have been a finnicky GPU to PCI connection. I pulled the GPU and tried it another PCI slot.

Same freeze. Same 'b2' terminal debug code on the mobo.

- A

 

[DavidM012]

Yes Motherboards fail particularly when the PSU is a bit old and waff and delivering too much voltage due to capacitor degradation. It's fairly critical to ensure the PSU isn't defective in any way.

 

[Bearmann]

If you have another PSU with its own cables, you don't have to snake all the cables through the case. Just disconnect the the 24 pin and accessory MB power cables from the MB and disconnect the GPU power cables from the GPU. Plug only these cables from the new PSU to these areas, ignore the other cables, and try to boot up. Leave the new PSU sitting on the desk with the cables going in through the removed side panel.

 

[Adamsan11]

Update:

• Neighbor had an old PCI GPU lying around (Radeon HD7770). Swapped out the GTX 1070 for that. Tried booting. The fan on the GPU may two loud starts (like 100% output) and then throttled down to a baseline speed. No graphics output at all, but this time I consistently got Debug code 97, i.e. "Console Devices Output Connect".
• Tried one other PCI slot with that HD7770. Same effect: Code 97.
• Switched back the GTX 1070 in an altogether new PCI slot and code b2 returned. Same as the original problem.

No multimeter to be found.

The neighbor said the old GPU was working fine when it was upgraded, so presuming it's still in good order, two different GPUs struck out in this mature platform. So:

1) The GPU is faulty

1. The mobo spontaneously forgot about it's legacy PCI settings (or has started to failed in some way, it is 8 years old)
2. I'm not getting enough power

I'm sure there are more possibilities, it's an ancient machine.

- A

 

[Adamsan11]

Update: holy crap!

I left it running while frozen after last attempt and was shocked to see a "windows crashed do you want a repair restart or standard restart" and I chose standard and wouldn't you know it, the nuttiest thing happened.

1. Starting windows icon was offset considerably down and right on the screen,
2. Took forever for Win 7 to come up (over 5 min),
3. And it when it did, it was unreadable since the screen 'tore' from sending the wrong resolution to the monitor and I could not go any further. Had to reboot.

But I was delighted because I have been to that place before -- when I installed the GTX 1070 2 years ago. The BIOS needed me to choose a legacy PCI setting for the boot process to work two years ago, and until I figured that out, 1 + 2 + 3 always happened. Once I chose that setting in the BIOS, it ran perfectly.

So my guess is the mobo battery died and undid the BIOS setting I enabled 2 years ago and I just need to re-enable it in the BIOS?

And that also helps me, b/c when this happened two years ago, it was like the comp was in slow motion for 10 minutes. The comp wasn't acutally freezing, it was just booting at 1/100 the normal speed so I thought it froze. I just have to mash Del / F2 whatever to get the BIOS to show up and I may be all set.

- A

 

[Adamsan11]

And my problem has been resolved.

That's insane.

DEL at boot didn't seem to work but holding F2 (a gigabyte standard BIOS key, I think) through at least one hard restart and pow, I was looking at the BIOS. Flipped the PCI setting to whatever the "Legacy" option was and poof. My eight year old computer is good to go.

If you are in this unbelievably slow boot problem with a 'new' GPU on an old comp, getting to the BIOS like this took a few tries, the comp isonly responsive for a quick window of time at boot, but when you scale it up to the boot times I was seeing, it was hard to time it. I ended up leaning on the F2 key (check your mobo manufacturer for its key, in this case the splash screen indicated key was a different on and did not work).

But this has happened to me twice, and legacy PCI in the BIOS sorted me out. My only reasonable guess here is that the mobo battery died and (for whatever reason) the BIOS setting were forgotten / reverted somehow.

- A

 

[DavidM012]

Wow! Amazon has got some multimeters!

 

[Bearmann]

Glad you got it working!