[SOLVED] No power to GPU or fans, will not post after motherboard swap. Please help!!!

[Rasco-J]

New builder here... I had to swap out my motherboard for a new replacement since there was a problem with the built in Bluetooth on my old one.

I had to flash my BIOS to the new version since I have the new Ryzen 7 5800X. When I switched on my PSU, I could see the RGB on the motherboard turn on, but no fans, no power to my GPU, nothing. I can see that my START button is lit up, but not the error code indicator.

Everything was working on my old motherboard... Did I just get unlucky and was sent a faulty replacement motherboard also? I have been searching these threads and I have been troubleshooting everything from swapping out RAM one by one to disconnecting everything except my GPU, RAM, and processor. I’ve tried to make sure that my RAM was properly seated right, and my GPU also. I checked all of my connectors and tightened them and they all seem fine. I’ve reset my CMOS too, and tried re-flashing BIOS three times, but that didn’t work.

I even tried all of these steps in this thread too: https://forums.tomshardware.com/thr...deo-output-troubleshooting-checklist.1285536/

Here are my specs:

ASUS CROSSHAIR ROG HERO VIII (Wi-fi) (old and replacement)
AMD Ryzen 7 5800X
AMD Radeon 6900XT
Asus ROG Thor PSU 850W
Corsair Dominator Pro 3600Hz 32 GB (4x8)

I’ve run out of ideas... Can someone Please help?!?

 

[helpstar]

tried re-flashing BIOS three times, but that didn’t work.

How does it not work? Does it flash, restart and doesn´t show a picture or is it differently?

Which BIOS version did you try?

The USB pen drive for flashing is disconnected while trying to boot normally?

All power cords plugged in thoroughly? ATX12V 8pin, all to GPU?

Are the CPU pins damaged somehow?

Did you reset the CMOS by jumper?

RMA this replacement as well

 

[Rasco-J]

How does it not work? Does it flash, restart and doesn´t show a picture or is it differently?

Which BIOS version did you try?

The USB pen drive for flashing is disconnected while trying to boot normally?

All power cords plugged in thoroughly? ATX12V 8pin, all to GPU?

Are the CPU pins damaged somehow?

Did you reset the CMOS by jumper?

RMA this replacement as well

How does it not work? Does it flash, restart and doesn´t show a picture or is it differently?

Which BIOS version did you try?

The USB pen drive for flashing is disconnected while trying to boot normally?

All power cords plugged in thoroughly? ATX12V 8pin, all to GPU?

Are the CPU pins damaged somehow?

Did you reset the CMOS by jumper?

RMA this replacement as well

Thanks for the response! For flashing BIOS, I followed the same method when I built the PC on the previous motherboard, I pressed BIOS button down 3 seconds with the new BIOS renamed properly on my USB drive. BIOS flashed repeatedly until it stopped after a few minutes. Nothing happens after that, no boot, no picture, no lights or fans spinning. Just RGB and start button. No lights to RAM, no power to GPU. Tried hitting power switch and also tried pressing start button on motherboard, no response. Power switch was checked and it’s installed in the correct location and tightened.

The BIOS version I tried was 3202, I also tried earlier version of 3003 since 3202 was still beta but no luck.

Yes, I disconnected the pen drive before booting normally.

All power cords are plugged in tightly, I’ve checked each several times, including 24 pin and 8 pin to GPU.

CPU pins were checked prior to installing, CPU dropped in easily before retention bar was locked in.

Not sure what resetting CMOS by jumper means, but I’ve tried using the CMOS reset button and I’ve also tried removing CMOS battery, no luck. Does resetting by jumper make a difference? Any other ideas?

I’m about ready to send this motherboard back for return...

 

[helpstar]

please take some pictures of your build and upload to imgur.com and post the links

Try an older gpu if possible
try a different psu

 

[Rasco-J]

Thanks to you, I found the problem... After reading your response, I double checked everything, and even though I thought the PCU was installed correctly, I decided to double check as last resort. As I was removing the AIO, the PCU removed with it, stuck to the thermal paste. This led me to believe that the PCU was not seated properly with the retention bar. After re-installing, I got it to post using only 1 stick of RAM in slot 4. The other 3 RAM slots were throwing errors on the motherboard and did not allow it to post. When I did get into the BIOS settings, after a few seconds it would freeze up and no response from my keyboard or mouse. After days of research I saw one comment in one thread that a bent PCU pin can cause memory channels to fail. I should have done as you said and checked more carefully for damaged pins when I had the PCU removed the first time. So I again removed the AIO, checked the CPU and found one bent pin. I straightened the pin out, and that solved the problem. I now have all 4 RAM slots working. The last error was a CPU Fan error, but after a quick YouTube search, I set the fan alert to Ignore in BIOS, and was able to install Windows. I never thought the PCU was a problem because I was so careful with it and it was working fine on my previous motherboard. Hard lesson to learn for a new builder!