PSU or motherboard failure. What to try?
Posted on 2009-04-03
Our company historically purchased all it's PCs from a rather inept IT contractor. The only things the PCs have in common is that they use cheap hardware. This morning a user reported that his PC had stopped working and could not be powered up. I took it back to my office and I could not get it to boot. The PSU makes a whistling noise when connected to the mains supply and so I assumed it had failed. Swapped out for a spare, but this did not work. I took a third one from a PC I knew was good and this one behaves strangely. The fan runs as soon as the PSU is turned on. The tiny green LED on the MB is illuminated, but I cannot boot the PC using the switch on the front.
I've tried disconnecting all the internal hardware (SATA HDD, RAM, IDE CDROM), and taking out the BIOS battery and leaving it for a while. Doesn't make any difference and I'm out of things to try. Can anyone make any suggestions about what else to try before I declare the motherboard DOA and bin the PC?
I'm a little concerned in that we have a lot of these type of failures (three this week out of ~100 PCs) and I'm not a hardware engineer, so worry that I'm missing something simple and trashing good hardware...... Having said that for the last year we have been buying HP workstations instead and not had a single failure of any kind on those, so I wonder if it is the cheap hardware......
Any advice gratefully received.