Question GTX 1080 - No display, but also the motherboard is not detecting new GPU ?

[eeiren]

Hey all,
I've been trouble-shooting my secondary pc build for the last few days and I'm stumped.

It's made from parts from an older build with a new PSU + GPU, build:

GTX 1080
AMD FX-6350
Asus M5A78L-M
EVGA 650GQ Gold

I've put it together a few weeks ago, had issues with no signal but after reseating the RAM and resetting CMOS it was all good. PC has been working fine, shut off ok - the next day it was booting but with no signal to monitor. I assumed it might be a similar issue so took out RAM and tried again, then reset CMOS, then took out GPU and plugged it back in, re-connected all cables from PSU and motherboard etc. after this I was able to boot up but with the CPU's integrated graphics - the GPU is not being detected either by device manager or system information.

I then plugged the GPU into my primary PC:

GTX 1080 Ti
Asus Z170-A
Intel Core i5-6600K
EVGA 750 G5 Gold

The pc was booting up - I could hear the Windows boot sound, but no signal to monitor. I tried swapping out the HDMI cable between the motherboard & GPU, and also tried the HDMI from my secondary PC, with no luck. I assumed at this point it was the GPU. However no LEDs on my MB stay lit up after booting, and there are no beeps.

I then inserted my old GPU into my secondary PC which the MSI Radeon R9 390, and again it's not being detected by the PC.

I'm honestly at a loss as to what's going on, is it the GPU or the MB? Both? I assumed since I have 1080s in both the PCs, I would be able to switch and boot easily.

 

[JohnBonhamsGhost]

you don't mention the power supply make & model from either system.

 

[eeiren]

you don't mention the power supply make & model from either system.

Edited the post to add them in now, secondary PC: EVGA 650GQ Gold. Main PC: EVGA 750 G5 Gold

 

[JohnBonhamsGhost]

secondary PC: EVGA 650GQ Gold. Main PC: EVGA 750 G5 Gold

while the G5 series has been known to be of higher quality,
the lower wattage GQ series are not intended for high-performance/gaming systems.

if this GTX 1080 fails to function in any situation now, it was possibly damaged by the GQ PSU.

 

[eeiren]

while the G5 series has been known to be of higher quality,
the lower wattage GQ series are not intended for high-performance/gaming systems.

if this GTX 1080 fails to function in any situation now, it was possibly damaged by the GQ PSU.

Forgot to mention - this particular GPU and PSU have been working together fine for a few years now as it's from a family member. No errors or issues whatsoever.

If the GPU was damaged would it still light up, have fans spinning and allow PC to boot with sound (although no didsplay)? Apologies for all the questions, I'm not super techy

 

[JohnBonhamsGhost]

If the GPU was damaged would it still light up, have fans spinning and allow PC to boot with sound (although no didsplay)?

always possible.
there are many parts to a component like a GPU that can be individually damaged, or just malfunction on their own.

i imagine you have tried all output ports on the GPU;
HDMIs, DPs?
individual ports have been known to fail.