bad PSU causing mobo to not detect my gpu's??

bishopi5

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guys i need help badly, for a while i thought my mobo may have been playing up, just stupid issues, then a few days ago, i turned my computer off, and after it shut down, everything was still on, (inside my case), both GPU's (vapor X 7970's were on, Water cooler, case fans etc) although my monitor and keyboard and mouse were off, it was infact acting like it is off, but everything was still running... anyways i was not able to fix that, if i unplug my PSU it turns off, as SOON as i pug it back in it the system turns on by iself... it does not boot up untill i press start, but the system is on, even the hard drives are spinning.. it didn't bother me much as i expected it to be the MOBO which i knew was dodgy anyways, i just left my pc on, or unplugged, all was good. My psu is a strider gold 1200w btw, So a few days after this power issue occured, i turned my pc off, (having to pull the cord to do so) but only after all was "shut down", turned the PC back on in the morning, and boom, no display... i have both my displays plugged into my top card both using DVI, never had issues... restarting / clearing cmos / switching PCIe lanes / ram all the normal shit, did not work, no signal.... the computer was deffintely booting normally and no beeps, it was literally sitting in windows 8.1 login screen waiting for me to login, i just could never get signal... so today i went and bought a MOBO as i "knew" that was the issue, after hours of rebuilding, everything looks as shiny as the day it was bought, new MOBO is z87 fatality killer, Plug PSU in to see if my new mobo has fixed my signal problem... and to my horror, the system powers on by itself again... i was shattered, i knew when i booted it up i would be facing the same problem, As i am now, the new MOBO will not detect ANY of my GPU's in the PCIe slots, just reads as empty, as im sure my old one was i just was not able to get any signal from MOBO because i had no video output on the MOBO. So im facing the exact same issue, Please help meeee, could a faulty PSU be causing all this? Could a faulty PSU power the system completely normally but just not let it read my GPU's???? both of them are fully powered up.... fans spinning, blue bios light on, sapphire logo on, yes the powert cables and eevery cable in correctly... wtf my head is fucked
 

theradeonxt

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Hello. Here are some thoughts off the top of my head:

1. System turns on when you just plug in the power supply - you could check in the Bios for settings related to power on / soft off (Acpi related i think), but this would only happen after a power outage. I think this might mean a short on the PSU (think in terms of intentional shorting to start the system without a power on switch).

2. Is the system fine when you run the display on the iGpu (assuming you have)? Or on one 7970 at a time?
Run the display off iGpu with one 7970 and see if Gpuz / Catalyst driver see the card.

3. If you can, test one or both Gpus on another system, see if they register as "Empty" as you indicated. Try another PSU.

4. If you have a dual Bios option on your cards try switching to the other Bios.

Best case the PSU is faulty, worst case the Gpus were damaged in the process.

Take care.
 

theradeonxt

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Oct 4, 2014
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Hello. Here are some thoughts off the top of my head:

1. System turns on when you just plug in the power supply - you could check in the Bios for settings related to power on / soft off (Acpi related i think), but this would only happen after a power outage. I think this might mean a short on the PSU (think in terms of intentional shorting to start the system without a power on switch).

2. Is the system fine when you run the display on the iGpu (assuming you have)? Or on one 7970 at a time?
Run the display off iGpu with one 7970 and see if Gpuz / Catalyst driver see the card.

3. If you can, test one or both Gpus on another system, see if they register as "Empty" as you indicated. Try another PSU.

4. If you have a dual Bios option on your cards try switching to the other Bios.

Best case the PSU is faulty, worst case the Gpus were damaged in the process.

Take care.
 

bishopi5

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i have tried all of the above ( except GPU in another machine, or new PSU ) , i am on my iGPU and both cards are plugged in and running but nothing registers in device manager / gpu - Z / catalyst, Except intel HD 4600, Could both my cards really get fried like that? With absolutely no evidence of damage? Just from unplugging the PSU once all was shut down? Or from system powering on early? Yes everything runs fine on the IGPU so it isnt my CPU or HDD or MOBO or RAM

Oh and yes i tried each card individually in all different PCIe slots before both of them went in..

and i have played with that power option in BIOS a few times, it does nothing, it was mean to stay OFF by default once the system surged, even once power is restored it is supposed to stay off.. but none the less i changed it, and i changed the primary adapter a few times, nothing. I "think" i can try a new PSU tomorrow, i just don't know if it has 2x 8pin connectors... also i can try putting an old HD 5770 or something in my machine....
 

theradeonxt

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The thing is, well, you can't know for sure. These days quality PSUs have built-in safeguards to prevent damage to other components and since the Gpus were not under load it's strange to say the least (but it CAN happen). So if we assume the Psu is fine then it's the Gpus we need to look into.

THIS is what caught my mind first: with the new Mobo you have the same problem in that the system "powers on" when plugging the power cord (meaning fans spinning, Leds, HDD) and you actually have to hit the power switch (as per normal usage). And if this is the case, does the same thing happen WITHOUT the Gpus? The thing is this is bad behaviour and should never happen (not even if you have a PSU without a power switch).

So I suggest you make absolutely sure the Gpu/s are ok (or not) and test them elsewhere before proceeding any further.

Edit: Well I guess the 5770 would at least help to check the 12V rail on the PSU. It's worth a try.
 

bishopi5

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Yeah i was thinking even if the PSU is damaged, It would probably power a 5770 anyways.. since it powers my system, im going to try my card in another system tomorrow. If it works ill be trying a new PSU... as that's the only reason i can think of as to why the system powers on by itself...
 

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