PC Not Starting: Troubleshooting

[j.shenfield0]

Hello all. I just reassembled my desktop PC after a move and buying a brand new case. After everything was reassembled, I pressed the power button. The lights on my GPU and RAM lit up briefly and the PSU, GPU, and case fans spun briefly, but immediately went out. That happens every time I press the power button. My motherboard does have a little green light labeled "SB_PWR+", which lights up when my PSU is connected to it and switched on, so some power is getting to the motherboard. I tried the PSU test with a paperclip and the PSU started up with the built-in fan spinning just fine. However, I don't have the right adapter to attach my case fan directly to my PSU, so I couldn't test it that way. I also tried resetting CMOS by removing the button cell battery for a minute and then replacing it.

After some googling around, it seems likely that the culprit is my motherboard. Is that the case? Are there any other troubleshooting tricks I can try?

 

[CountMike]

Take it out of the case and try with only elementary components.

 

[j.shenfield0]

Take it out of the case and try with only elementary components.

Take the PSU out? Also, what counts as an "elementary component"? I'm not familiar with the term.

 

[CountMike]

Take everything out and try with only CPU, RAM, PSU and if MB doesn't have built in GPU than your GPU too. It helps to have a speaker or buzzer connected to hear eventual beep POST codes.