A first time builder brought me a PC to look over in April. Specs are as follows: Micro ATX Cooler Master case, Asus TUF B450M-Pro mobo, Ryzen 5 1600, 16GB T-Force DDR4 3200 (2x8), Nvidia Quadro M4000 GPU, Zumaxpower 550W PSU (I think, it could have been another one), PNY 240GB 2.5" SSD, 1TB HDD. Cabling was a mess, but I fixed that and double checked compatibilities and didn't find any obvious issues. I plugged in a Win10 install stick and flipped the switch.

I think that first time, the fans started spinning and that was it. Here are the issues I eventually discovered with that build: First, 550W is barely enough. Shouldn't be a problem, but that could explain the partial power up. Second, the processor only supports DDR4 2777 without overclocking. Again, should not be a problem since RAM can be underclocked. Third, the cpu could be DOA. Again, this would explain the partial power up, but is more expensive to fix than the PSU. Fourth, the mobo could be DOA. I tried to leave that one alone because it's such a pain to replace the mobo.

Anyway, I replaced each part one at a time until it was basically a brand new machine. Keeping the mobo and processor model the same, I upgraded the PSU to a Marblebron 750W, and downgraded the RAM to DDR4 2777. Somewhere in there, I went through a period where I had to plug in a different power button to get even the fans to run. I RMA'd the mobo and processor at the same time to make certain they weren't breaking each other. It booted into my install stick once, but the drive I wanted to install windows on wasn't listed. I powered down and checked the cables. Next boot up only powered the fans again. After this, I discovered that this particular mobo/processor combo might need a BIOS update to work together. Maybe. There was one post in a dark corner of a forum, I don't remember which one. (I also swapped out the GPU for a tester I have on hand, to rule out the GPU needing more power or simply failing to display, or anything like that while working on the other parts.)

The third build in this case (I consider the point where it finally booted to be the second build) started by RMAing as many of the parts as I could. I ordered an MSI B550M-A-Pro and a Ryzen 7 2700G. I swapped in a Corsair CX550M PSU that had recently been tested in case the Marblebron was tired of playing. I used my MSI GeForce GT710 testing GPU. Now all the elements of the original design have been fully replaced. I flip the switch, check into the BIOS to make sure all the hardware is reporting correctly and playing nice, then try to boot into my install stick. Fans only. (insert off-color joke here.) WHAT IS GOING ON??? I did some digging and found that this mobo/processor combo might also need a bios update. Great. The current BIOS should work with 3rd gen Ryzen processors. Luckily the very next day, a used Ryzen 9 3900X fell into my lap. I installed it and now...... It doesn't respond at all again. no fans, no flashes, no nothing. I'm at my wit's end and the poor kid that brought it to me in the first place is probably not feeling any better. Oh, I also tried plugging in a different power button like before to no effect.

The case is the only thing that hasn't been replaced.
 
D

Deleted member 362816

Guest
Try to boot the pc by jumping the motherboard headers with a screw driver. this would rule out the case front panel having a short in it etc.
 
I'll do that to be thorough.... I don't think it will work, since it was working before the most recent processor swap and I've tried a different button.

Ok, I have tried that to no effect.

Normally I would assume this means the PSU isn't working. Or it's not plugged in. I am confident that is not the case, since it worked before the processor swap and I just physically verified that it is plugged in. Of course, I've been wrong before. The next obvious step is to swap out the power supply. Again.

Will update after completed.
 
Ok, tried two more PSUs. Same result. That would usually indicate a failed mobo. However, since I just changed the processor, I suspect that is the real cause. I have a Ryzen 5 1600 (somewhere, I couldn't find it), a Ryzen 7 2700x, and Ryzen 7 5600G on hand to swap in to see if the fans come back.

Any bets on which part is the problem?