Computer Does Not Work At Home But Works in PC Repair Shop
I have never encountered this phenomenon. No, it's not phenomenon - it's anomaly that defies logic.
My computer was left for 1 week in a mixed standby hibernate state. I think it's S4, don't remember. It was plugged in to UPS. When I wanted to wake it up from standby, it didn't. Then I pressed on power button on my case and it made no difference.
Tried testing PSU alone, cooler was spinning. Used multimeter to test voltages and all was within normal range. Sent my under warranty motherboard to PC repair shop, they checked, said it works and updated BIOS as a bonus. Received motherboard back and same thing.
This time I took motherboard, CPU, RAM module and PSU to a local PC repair shop. Yes, that's second PC repair shop! They tested, all was working but when I tried to turn it on at home, again it didnt. Plugged power cable to UPS, disconnected UPS from mains to make sure PSU runs from UPS battery and it didn't work. Tried different power cable, it didn't help. Tried in different rooms but to no avail.
I am going crazy. Nothing makes sense. This is unreal.
CPU: AMD Ryzen 5 3600X
Motherboard: Gigabyte B450 Aorus Elite
RAM: 2x8GB Corsair Vengeance LPX
PSU: Corsair TX650M
Solution 1:
Looking at the comments, you did what you could do to emulate what was at the shop. Ideally, you would try to boot the computer with the PC_SPKR plugged in to the motherboard (the one that beeps on a successful bootup), remove all the RAM, and power on to hear 3 beeps (showing the motherboard is likely working).
If the computer appears dead, and the power button / shorting out pins on the motherboard is not helping, then I'd start looking at the Power Supply - both the unit, and the circuit in your home.
Can you bring it to a friend's house to try? If it starts up there, then we proved it's a wiring issue in the home. If it doesn't start up there, then it's more evidence there is something wrong with the computer.
Solution 2:
If it's not pure coincidence - which is the most likely explanation - here are some more theories:
- Your UPS is broken - or is outputting a nonstandard voltage that's not working well with your power supply. If you put a signal analyzer or oscilloscope to a power signal, you will see some pretty interesting things, especially on the output of cheap UPSes. Remedy #1: Don't use the UPS.
- Your wall power is nonstandard - I'm not sure what country you're in, but I once measured 70V from the wall socket. Needless to say, only random things worked. Other explanations may be electrical noise on your home circuitry. Remedy #2: Try at a friend's place.
- Your PSU is damaged. Remedy #3: Try another PSU
- It's some sort of software issue. Remedy #4: Try using Linux for a while and see if it does the same, that eliminates software as the issue.