[SOLVED] Desktop pc won't power up because of graphics card?

[emitfudd]

I posted last night asking if my psu is most likely at fault because my pc completely died while I was playing a game. I got no replies. I have more information now and could really use some help.

I removed all the cables from my Seasonic Titanium 850 psu except for the 24 pin cable going to the motherboard. I did the paperclip test and got the fan to spin. I plugged the 24 pin back into the MB and tried to power up the pc with all other cables still disconnected. Got nothing. I tried unplugging and plugging the power cord back into the psu a few more times. The second time when I pressed the case power button I got about a 1/2 second of action. Lights, fans, etc. then it shut down again. The third time all I got was a double click from the MB. Next try everything powered up as normal like it fixed itself. Strange. Now I have started plugging cables back into the PSU. If I plug in all of them I am back to a dead computer. If I leave the CPU cables plugged in and the GPU cables disconnected it powers up as normal. As soon as I plug in the GPU cables it is dead as a door nail. Gigabyte 1080ti. Everything seems to point to the GPU being the faulty component. How is it possible that a bad GPU can prevent the pc from powering up at all? Is there any way to test a GPU? I am really hoping it is not the GPU because we all know there is no stock of 3080's and even buying another 1080 ti, the only option is used at a huge price.

Does anybody agree/disagree that a GPU could completely shut down a pc? Thanks.

Corsair 780T case
Asus Maximus IX Code mb
Corsair Vengeance 32MB DDR4 ram at 3000Mhz
Gigabyte 1080ti
2x Samsung 960 EVO 500MB
Seasonic Titanium 850 PSU
I7 7700K CPU OC'd to 5.0 Ghz

System is about 4.5 years old with at least 5 to 6K hours of gaming use.

 

[Aeacus]

Does anybody agree/disagree that a GPU could completely shut down a pc?

If the hardware is faulty, it can, yes, stop the rest of the PC from booting. Also, if you can power on, and boot to OS, with GPU removed and your monitor cable connected to MoBo, it is safe to assume the GPU is at fault.

At this point, what little you can do, is try plugging GPU to 2nd or 3rd PCI-E x16 slot. Since it is possible that the 1st PCI-E x16 slot on your MoBo is faulty.

Other than that, there are 2 other things you can do, but those require 2nd PC:

1. Plug your 1080Ti into 2nd PC and look if it works there.
2. Use 2nd, known to work GPU in your PC, to look if your PC works fine.

For GPU replacement, and for equal or better performance, look towards 3060 Ti / 3070 and up, on Nvidia side; and RX 6800 and up, from AMD side.

 

[emitfudd]

I just tried moving the GPU to the empty slot below it. That didn't change anything. I was able to power on the pc a few times with the GPU cables disconnected, as before. Now I am not able to get it to power up at all again. Sometimes if I unplug the CPU cable as well it will power up, sometimes not. I am wondering if the PSU is having issues and doesn't have enough power for the GPU. I have a new one coming tomorrow and will try that.

You mentioned booting to OS with monitor cable connected. I don't have onboard graphics so would that work?

 

[DSzymborski]

An i7-7700K has integrated graphics.

 

[emitfudd]

An i7-7700K has integrated graphics.

I had no idea the 7700 had integrated graphics. Thank you.

 

[emitfudd]

If the hardware is faulty, it can, yes, stop the rest of the PC from booting. Also, if you can power on, and boot to OS, with GPU removed and your monitor cable connected to MoBo, it is safe to assume the GPU is at fault.

At this point, what little you can do, is try plugging GPU to 2nd or 3rd PCI-E x16 slot. Since it is possible that the 1st PCI-E x16 slot on your MoBo is faulty.

Other than that, there are 2 other things you can do, but those require 2nd PC:

1. Plug your 1080Ti into 2nd PC and look if it works there.
2. Use 2nd, known to work GPU in your PC, to look if your PC works fine.

For GPU replacement, and for equal or better performance, look towards 3060 Ti / 3070 and up, on Nvidia side; and RX 6800 and up, from AMD side.

So if I am understanding correctly, I should leave the GPU mounted to the motherboard, don't plug in the GPU cables to the PSU, connect the monitor cable and see if everything powers up as usual?

Edit: I found the display port and hdmi port on the back of the motherboard. So I am going to try this with the gpu completely removed from the system.

 

[Aeacus]

I should leave the GPU mounted to the motherboard

No. Take it out of the PC completely.

 

[emitfudd]

No. Take it out of the PC completely.

Ok, I have confirmed the PC has powered up normally with the GPU completely removed from the PC.

I am still going to try hooking up the new PSU when it arrives tomorrow just to see if by some small chance it isn't providing enough power to the GPU.

I am also going to try putting my old 750 ti into this computer to see if it has enough juice to play games while I am shopping for a 3080.

Thank you for the help.

 

[mdd1963]

Do not mix any old modular cables from old PSU with the new PSU, as different pinout standards at the PSU insertion points can have disastrous consequences on GPUs, mainboards, and/or SATA devices...

 

[emitfudd]

Do not mix any old modular cables from old PSU with the new PSU, as different pinout standards at the PSU insertion points can have disastrous consequences on GPUs, mainboards, and/or SATA devices...

I ordered the exact same PSU. Seasonic titanium 850. Do you think the modular cables will have changed from 2017 to now?

 

[Aeacus]

Do not mix any old modular cables from old PSU with the new PSU, as different pinout standards at the PSU insertion points can have disastrous consequences on GPUs, mainboards, and/or SATA devices...

It's good advice, especially when you're switching PSU brands. But when you have in-depth insight to same brand PSU models, switching the cables isn't necessary.

Do you think the modular cables will have changed from 2017 to now?

No.

In 2016, i bought my Seasonic PRIME 650 (80+ Titanium) PSU and some time later, i also bought CableMod paracord sleeved power cables, to replace both stock PSU cables, within my two main PCs (Skylake and Haswell). At that time, Haswell build was powered by Seasonic M12II-850 EVO. In Dec '20, i replaced the aging M12II-EVO series PSU, to Seasonic PRIME Ultra 650 (80+ Titanium) PSU, without needing to change the sleeved CableMod cables, since they are universal to all fully-modular Seasonic PSUs. I have three sets of CableMod power cables for my Seasonic PSUs (in red, blue and green colors), that i can switch around freely, if i desire.

Seasonic PRIME Ultra (80+ Titanium) PSU, after OneSeasonic initiative, was renamed to Seasonic PRIME TX-series, which you can buy at current date.
So, even if you had PRIME 850 before, and now have PRIME TX-850 (same as PRIME Ultra 850), the power cables and PSU side pinouts are same between the two PSU series.

There were only very minor changes between PRIME and PRIME Ultra/TX-series. Once PRIME Ultra was released, i contacted Seasonic directly about the changes and got the following as an answer:

Thank you for your email and interest in our PRIME Ultra Series.

PRIME Ultra will introduce few updates for this Series:

• General optimization (capacitors for example)
• No more inline capacitor for PRIME Ultra 1000 Titanium and Platinum and Gold. Previous models has some on PCI-E and motherboard cables for example.
• New accessories: PSU tester and SATA adapter compatible with SATA 3.3 used by some HDD recently released on market. Some SATA cable(s) will have connectors at 180° instead of 90°.
• Shorter case (140mm only) for 550W, 650W, 750W in PRIME Ultra Platinum and Gold.

For the 600W Titanium Fanless, it's a model expected since few months now and it will be on market very soon.

That being said, you are safe to use the power cables of your old PSU.

 

[emitfudd]

My new PSU arrived and I installed it. I verified it works with the tester that came with it. I hooked up the GPU with the new PSU cables and new power cord and the PC still won't power up. I guess this confirms that it is in fact the GPU that died.

I was really hoping it was the PSU. Now i stuck with my old 750ti until I get lucky enough to find a 3080 or even a 3070 at a decent price. I signed up for EVGA's queue but from what I have read I won't get an email to purchase anytime soon.

 

[Aeacus]

Nice to hear you got your issue solved.

Now i stuck with my old 750ti

Think about this way, if you wouldn't have your old GTX 750Ti, you'd be stuck using CPU's on-board graphics (iGPU), which in terms of performance, is much worse than GTX 750Ti.
Comparison: https://gpu.userbenchmark.com/Compa...-Kaby-Lake-vs-Nvidia-GTX-750-Ti/m178724vs2187

All-in-all, i prefer CPUs with iGPU for this very reason (Intel CPUs, except F-suffix and AMD APUs), since when dedicated GPU happens to die, you have 2nd source for GPU and you can still use your PC (web surfing), compared to not having iGPU at all (AMD Ryzen CPUs, Intel F-suffix CPUs), where you can't use your PC without dedicated GPU at all.