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Short description (readability and 150 char title limit):
I had a power blackout+brownout recently. The picture on screen would not show. Upon further investigation, the monitor would turn on ONLY in safe mode, until I uninstalled the driver. Drivers were reinstalled, and the monitor turns off after "Starting Windows". Otherwise, it can boot into Windows. I have uninstalled (and cleaned) all the drivers before reinstall of older ones.

Is the GPU bad?

To reiterate, the following events took place:

  • power goes out for over a minute
  • a few seconds after lights go out, thunder rolls
  • power browns out again or goes out briefly (I was in another room, I could only see the lights dimming to zero for a brief moment)
  • thunder rolls again

Next:

  • when I turned my computer back on, the picture didn't seem to display

    • it should be noted here this was a "salvaged" Samsung Syncmaster, which entire company apparently has notoriously buggy and/or defect-ridden power supplies (Google it up, esp. LED TV), often trapping themselves in OFF mode, or eternally flashing standby lights.
    • Thus the deeper problem was not immediately evident. Due to the power outage, the The monitor was refusing to turn on (this monitor has to be kept on--I have even disassembled it to look for bad capacitors, per an EEVBlog post).
  • Switched bad monitor for my old one. It became clear:

  • blue power LED showed yellow AFTER the POST--sometimes the computer would even restart in a loop after the Windows Logo.

Further research was done (I read and skimmed a statistically large enough sample of the relevant threads on the Internet), and took the following actions:

1) Boot into Safe Mode (with networking) -- this was the only and surefire way to get in.

2) Changed resolutions to something the good monitor might scale to, since the "bad" one was 1920x1200 > 1680x1050 of the good one.

3) Restarted with various resolution settings, removing VGA, updating or changing driver to at least 2 different versions including the working one I had installed a year ago (AMD has been updating it sometimes).

4) Removed device in DM, "deleted" driver in checkbox, ran DDU, and ran AMD cleanup utility, in safe mode.

5) Restarted, monitor works. Install driver, monitor turns off.

Conclusions:

1) NO graphics driver I installed made a difference. The computer either reset in a loop or made it to a the login screen with no video signal, but full sound and USB microphone feedback. 2) Installing the monitor driver and ICM profile in safe mode did not change anything, either. 3) The screen turns off as soon as the "Starting Windows" logo disappears, every time.

4) With no driver installed, I can boot into "regular" mode with a picture. Otherwise, the screen only works in Safe Mode.

Is my GPU toast? Or should I try uh, piggybacking another ATX supply to use the 6-pin connector?

This is on an HP-branded Tyan K8WE derivative OEM board used in an (old) workstation. The power supply is a Delta DPS-750CB that has been abused by a relative turning the circuit breaker off in anger, retaliation, etc. Both monitor and PSU were connected behind the ostensibly-functional Surge Master (1kJ prot. or so?) at the time of the lightning strike(s).

  • Wild guess: Your card has multiple video outputs, the driver prioritizes them differently than safe mode, and something happened (possibly damage from the surge) to make the card think that something is plugged into one of the other ports (HDMI seems to often be a culprit). Then your video card hasn't actually failed, it just is sending the signal to a port other than the one where your monitor is connected. If you could tell it to enable all outputs, you'd get signal again. – Ben Voigt Oct 4 '17 at 19:55
  • Well it has 2xDVI. I believe I have tried both. It's an MSI R7790. – Mark C Oct 4 '17 at 21:02
  • In the past I had a card that liked to choose the HDMI as primary display (even when nothing is plugged in there), so don't limit your testing to only DVI. A quick search shows MSI R7790 with 1xHDMI, 1xDisplayPort, 2xDVI, although there are definitely multiple models by MSI with the same chip, and I don't know if all of them have the same selection of outputs. – Ben Voigt Oct 4 '17 at 21:40
  • @BenVoigt Sorry, I still had them covered up, so I had basically forgotten about them. Well, I don't have any cable, and I have reseated the card in its slot (I think the other PCIe is bad). The only thing I could do is clear the CMOS. Not sure if the VGA has a reset. I don't have cables for the other. Just as an aside, do you think this question doesn't show "research effort"? I literally went through to the end of every distinct solution online. – Mark C Oct 4 '17 at 22:28
  • Try another GPU as a conclusive test. – harrymc Oct 9 '17 at 10:12
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If you've tried all the GPU outputs, and all of them exhibit the same behavior, there are a couple possibilities.

  1. Your PCIe slot is toast - test by using the GPU in a different machine or PCIe slot or a different GPU in the same machine same slot
  2. Your GPU is simply toast. I had an XFX HD 6870 that exhibited the exact same behavior.

If your GPU is toast, there's no way to save it. It's a chip problem. It's possible you could reflow the chip, but it's unlikely you'll be able to save it.

Buy a GTX 1060 and enjoy the performance boost.

| improve this answer | |
  • Thanks Daniel. I still need to try it in another computer. This slot works with an older (and less powerful, but more power-hungry??) Nvidia graphics card. @Daniel Update: Actually, Newegg says its warranty is 3 years, so I am just inside the window if it is still intact (I don't recall using any UPC code as a mail-in rebate). – Mark C Oct 10 '17 at 22:40
  • I would send it in for a warranty replacement. Take advantage of that before it runs out – Daniel Oct 11 '17 at 4:58
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    If this answer helped solve your problem, don't forget to mark it as the solution @MarkC – Daniel Dec 6 '17 at 10:19

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