Solved PC won't boot with GPU connected to PSU, boots when isn't.

phillpower2 said:

For clarity and to avoid any possible confusion, a computer has not booted until the user is in a fully working OS such as Windows.

With the above in mind it is possible that the MB is failing the power on self test ( POST ).

What is the exact model name or number of the 750W Corsair PSU and is it out of the box new.

Do you have the keyboard connected to one of the black USB 2.0 ports.

I concur with Peter regarding the replacement MB needing a BIOS update and likewise we need to know the RAM details.

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Hello, Phil.

You are right, I should have invested time in finding the right terminology and write more accurately.

I guess, "Once again the PC will not power up when the GPU is connected to PSU" would fit better.

The PSU is CORSAIR CX-M Series CX750M 80 PLUS BRONZE and is not out of the box new, but I can say
I got it from a reliable source, since I know him personally. I'm pretty sure it's a faultless device.

I have no keyboard connected.

About the Q-flash, I've never done it before, but it should be pretty straight forward process as i read.

So, i download the latest bios for the board, format USB flash in FAT32, extract the bios onto the flash,
strip everything out that i can from the board, power up the board, insert the flash with the latest bios
in usb port next to the q-flash button, press it for a couple seconds and that should do it, right?

I read something about renaming the BIOS file itself for GIGABYTE boards, is that necessary?

Please correct me if any of the steps are wrong.

phillpower2 said:

Good choice of RAM to pair with the CPU.



Corsair make decent PSUs but they must be used for their intended use and like all PSUs they are only reliable when covered by warranty, the PSU to which you refer is not only not out of the box new but also not covered by any warranty and not being used for the intended use, what Corsair recommend here that the PSU be used for;



The PSU was rated as Tier C • Recommended for cheap mid/low-end systems here



You 100% need a keyboard attached as described in my reply #19 or the power on self test will fail when the BIOS cannot detect a keyboard.



If you flash the BIOS with no keyboard attached as was previously advised you very well may brick the MB.

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Hello, I'm embarrased but happy to inform you that I found the culprit.

It turns out, just like you said, phill, that PSU was not reliable. I should have known better.
Never skimp on the PSU, is the lesson I leared i guess.

It was originally bought for gigabyte ab-350 and R3 1500x and it worked well
for couple days. Didnt think it could go bad like that so sudden, since it's a corsair..right.

Anyways, just ordered an RM850X, think this one should be a bit more reliable.

Do you guys think 4080 would fit well in this system, or should I get 3080TI?
I want to do some 4K gaming, but since my TV can only run 4k60hz, i'm wondering
if 4080 would be overkill. Would 3080TI struggle to produce 60 fps in this system?

I'm also aware it's relative from game to game and the settings what FPS it will output.

And one last question, would I get any perfomance increase if I got the
G.SKILL TRIDENT Z NEO DDR4 3600, CL16, DIMM 288-PIN, over the current RAM?

Bruce said:

in post #20 you mention Kingston Fury Beast KF432C16BBK2 but not how much of it you have?
from the number I can guess it is DDR4-3200 CL16 and probably a kit of 2.

so you are probably only changing the hertz from 3200 to 3600.
not a big jump.
yes - a benchmark test will show better numbers.
but if you would notice the improvement, I would say probably not.

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Yup, you are correct. I would be changing only the Hz.

I will save some cash then.

Thanks for the reply.

Also, the brand new PSU just came in, the PC is now fully operational.

Sorry for the confusion, I should have been more thorough with investigation.

Thank you everyone for your time.

Best regards, have a nice day.