Question New PC build will not POST. Please Help!

[shazeebra]

I assembled my PC and tested it with no graphics card. Mobo RGB lights worked, fans spun on, and keyboard received power. Everything seemed good.

A few days later, I inserted the graphics card (GTX 750i) and powered on. Everything is still fine but no display because I forgot to plug in the 6-pin power cable to the card.

Here's where things get wonky.

I plugged in the power connector to the graphics card, and powered on. This time the mobo lights did not turn on, the front power switch no longer turns off the machine (I have to use the back switch now), keyboard no longer gets power (I tried every USB port), but the CPU & system fan still spin. Display shows nothing and I can't get to the BIOS screen via [Del] because my keyboard doesn't work.

Naturally, I took out the graphics card and hoped it would go back to normal, but to no avail. I disassembled everything and reassembled it. Tested all connections to make sure they were secure. Reset the CMOS. Still nothing. I don't have a mobo speaker, so I can't verify if it POST beeps or if it lets out beeps for bad/no RAM.

Based on all of that, I guess I may have short-circuited or fried the mobo somehow on accident, but I can't verify. It could potentially be a PSU failure too, but I'm not skilled enough to self-diagnose the cause of all these problems.

If you know how to fix this, please help! Any step in the right direction would be appreciated.

Here is my build:
AMD Ryzen 5 2600
Gigabyte B450 i Aorus Pro WiFi Mini-ITX
GSkill Ripjaws V DDR4 3200MHz 2x8GB
Inland Premium NVME M.2 SSD 512gb
ASUS GTX 750i
GameMax 600W Semi-modular 80+ Bronze PSU (GAMEMAX VP-600-M-RGB )

 

[DMAN999]

I would first check to make 100% sure that the cables from the PSU are fully seated in the PSU sockets and at the other end as well.
Especially the 24 pin and 8 pin power cables to the MB.
It is pretty common to have one or more get bumped slightly loose when adding new components into a case.
I've done that myself a few times.

 

[shazeebra]

I would first check to make 100% sure that the cables from the PSU are fully seated in the PSU sockets and at the other end as well.
Especially the 24 pin and 8 pin power cables to the MB.
It is pretty common to have one or more get bumped slightly loose when adding new components into a case.
I've done that myself a few times.

I went and doubled-checked just now, and the connections seem very secure to me for both cables on both ends. Trust me, I was really hoping this was just a cable connection problem too haha

 

[DMAN999]

Try to Clear CMOS using these steps:
Unplug the PC (PSU).
Then press the Power Button for at least 30 seconds.
Use a flat headed screwdriver to short the CLR_CMOS Jumper (Touch both jumper pins with the screwdriver) for at least 15 seconds.
Plug the PC back in.
Press the Power Button to turn the PC on.
Repeatedly tap the DEL key
If a screen comes up telling you to press the F1 key, do that.
Set the Optimized Default settings and Press OK (this is on the EXIT tab)
Save and exit the BIOS.
Tap the DEL key again to enter the BIOS and change any settings you want changed then save and exit again.

CLR_CMOS jumper location is shown on page 13 of your Manual:
https://download.gigabyte.com/FileList/Manual/mb_manual_b450-aorus-pro-wifi_1002_e_190528.pdf

If that doesn't work I'd test the PSU like this:
https://www.lifewire.com/how-to-manually-test-a-power-supply-with-a-multimeter-2626158

 

[shazeebra]

Try to Clear CMOS using these steps:
Unplug the PC (PSU).
Then press the Power Button for at least 30 seconds.
Use a flat headed screwdriver to short the CLR_CMOS Jumper (Touch both jumper pins with the screwdriver) for at least 15 seconds.
Plug the PC back in.
Press the Power Button to turn the PC on.
Repeatedly tap the DEL key
If a screen comes up telling you to press the F1 key, do that.
Set the Optimized Default settings and Press OK (this is on the EXIT tab)
Save and exit the BIOS.
Tap the DEL key again to enter the BIOS and change any settings you want changed then save and exit again.

CLR_CMOS jumper location is shown on page 13 of your Manual:
https://download.gigabyte.com/FileList/Manual/mb_manual_b450-aorus-pro-wifi_1002_e_190528.pdf

Thanks, I will go try this, and report back on what happens

 

[shazeebra]

Try to Clear CMOS using these steps:
Unplug the PC (PSU).
Then press the Power Button for at least 30 seconds.
Use a flat headed screwdriver to short the CLR_CMOS Jumper (Touch both jumper pins with the screwdriver) for at least 15 seconds.
Plug the PC back in.
Press the Power Button to turn the PC on.
Repeatedly tap the DEL key
If a screen comes up telling you to press the F1 key, do that.
Set the Optimized Default settings and Press OK (this is on the EXIT tab)
Save and exit the BIOS.
Tap the DEL key again to enter the BIOS and change any settings you want changed then save and exit again.

CLR_CMOS jumper location is shown on page 13 of your Manual:
https://download.gigabyte.com/FileList/Manual/mb_manual_b450-aorus-pro-wifi_1002_e_190528.pdf

If that doesn't work I'd test the PSU like this:
https://www.lifewire.com/how-to-manually-test-a-power-supply-with-a-multimeter-2626158

I tried this, but still nothing! Currently, I don't have a multimeter to check the PSU with

 

[DMAN999]

Any chance you have a friend that will lend you a PSU or let you try your GPU in his PC ?

 

[shazeebra]

Any chance you have a friend that will lend you a PSU or let you try your GPU in his PC ?

So I actually got the GPU from one of my friends, and it worked fine in his build, so I can verify there's no problem with it internally at least. Unfortunately, I don't think he has a spare PSU though.