Device fails to power up.
Device fails to power up.
I simplified the situation by taking out my Noctula U12s Cooler to replace the thermal paste with the original Noctula product. I also used isopropyl alcohol to remove any leftover residue and dried it with a paper towel. Now my PC won’t power on, and I’m really worried. I took out the power supply unit and double-checked that all MB connectors were securely connected, but it still doesn’t turn on. Please help!
You press the power button but nothing occurs—no fans whirring, no sound? That’s unusual. If it works, it might be something minor like a faulty PSU, a disconnected wire, or a dead motherboard. Otherwise, it could indicate a more serious issue such as a malfunctioning board or internal damage.
I didn’t understand what occurred. I only changed the air cooler, reapplied thermal paste, and reinstalled everything. All components were fresh. How could something like this happen?
Truly anything could help. If there were any indication of activity from the power button press, I might consider something. However, when it doesn't respond at all—like it's completely inactive—the only options are to inspect and test every connection from the PSU to the CPU (including CMOS battery and all related wires). It could be a failed PSU, a bad cable, a faulty wire, or a defective board. If you have spare parts and skills, check everything thoroughly. Otherwise, take it to someone who can help.
I have a damaged JUSB pin on one port that I don’t use, but I’m confused about how just reapplying thermal paste and switching the PC on/off could cause this. If I put it on the floor, could I have disconnected a cable somewhere? I checked thoroughly but didn’t find anything. I’m feeling really stressed. I can’t test if my PSU is working because the fan doesn’t spin when idle. Do you know if there’s anything I can do to figure out the problem?
You might want to test another PSU if you have one available. You can even ask a friend to lend it, as it doesn’t need to be a high-performance unit since you wouldn’t have to connect everything to verify the issue. I think the problem could be with the motherboard or the PSU itself—since nothing powers on, it’s possible you shorted something while cleaning with isopropyl alcohol, though that seems unlikely. Make sure the PSU is powered on or try using a different power outlet to confirm. Check all components carefully so you can pinpoint the source. Double-check the MB—power button (PC case’s power button)—and ensure the cable is connected correctly. Refer to your MB’s manual for details.
I’m really concerned about this situation. It seems like something unexpected might have happened, but I’m not sure how it could have affected the system. Is there any chance the isopropyl could have damaged the motherboard? I’m puzzled by how reapplying thermal paste would cause such issues. Could a broken wire connected to the power button be the problem? I double-checked the connectors on the motherboard, and they look good.
I mentioned that shorting your main board is improbable, but the power switch cable should connect correctly to the main board—whether it's powered on or off. I’ll just send a few pictures so we’re aligned.
Here’s a revised version of your text:
These connectors are positioned at the lower right corner of the motherboard (usually). Which model are you using? Also, please disregard my dusty remarks about the PC.
Yes, those photos look nearly the same as on my PC. I am using a MSI X570S Tomahawk MAX WIFI. The cables were never detached or moved and everything is how it was when it worked. I can give an entire timeline of what I did: 1: Shutdown PC and unplugged all of my USB cables. 2: Moved desktop from desk and layed it on the floor (for more room). 3: Unscrewed and took off my Noctula air cooler. 4: Cleaned CPU of thermal paste with isopropyl along the chip and motherboard. 5: Put everything back together and moved it back on my desk. 6: PC did not turn on afterwards.