The PC does not start in the office, but it starts at home. Why?

Question

Iron

Hello everybody! I have an office PC. It was decided to upgrade the hardware on it. We took the processor (AMD athlon x4 340), mat. pay and opera. memory. The power supply (350 watts), video card (GF 8400gs) and hard drive were left from the old one. We assembled it, launched it, and we see that the computer restarts on loading the OS logo. When you try to restore or reinstall the system after a while, the monitor turns off, the keyboard does not respond, the same thing in the BIOS. We thought that the power supply was weak, so I took it home - everything started up. It doesn't work in the office. For the sake of interest, they returned the old hardware (the computer worked on it, albeit tight). The computer starts normally, the system boots, but after a short time the monitor turns off again and the keyboard does not respond. Please help with this problem.

Answer 1

There are few options here:
1. Faulty power supply - for example, the input capacitors have lost their capacitance noticeably. Well, there may be several other problems in the PSU. Checked in the SC without problems.
2. Different voltages at home and at work - in one case it works, because. fits within its limits, in the other - no longer. If other limits are declared, this is already a PSU malfunction. For example, if it is declared to work from 180 to 240V - and it is already turned off at 190V - this is a malfunction.
3. What exactly did they bring home? If the whole system - then there is only one explanation - while they were carrying it, it warmed up or cooled down, and it works in this form. This is a malfunction of the PSU or sometimes the motherboard. If one PSU was worn, then it is worth checking the power button on the system unit - a leak on it can give such glitches, and sometimes it is difficult to detect, because. may not always appear. It’s easier to turn off the button and turn on the computer by closing the contacts with a screwdriver (carefully!) If it stops turning off like that - here it is, the button - it’s enough to replace or solder it to the second group of contacts (usually there are two of them, the second is not used).
4. It is unlikely, but it also came across - there is significant interference in the supply network (for example, somewhere nearby something sparks strongly at the substation, or some kind of arrester flashes), and the PSU reacts poorly to this. True, a serviceable and normal PSU is usually a damn thing, but some catch glitches, and even UPSs go completely crazy. There may also be such interference near industrial facilities or with the railway.