Bad mains power

I have a situation wherein I am beginning to think that the problem is with the mains power or severe interference. I rebuilt my nephews computer which had been running a Jetway 663ASpro board for some time with Windows 2000. It suddenly quit and it appears that the board and the power supply were dead. I thought "well that happens, particularly with mediocre power supplies. I replaced the power supply with an Antec True Power 550 and put in a virtually unused Asus AS8V with a New Barton 2800 processor and 1 Meg of new Kingston ram. I burned it in overnight after installing everything. He took it and it quit within the week. As I was considering the problem, his father (my brother in law)'s ENpower computer of 2 or 3 years age failed. It also had a bad power supply and motherboard. I should have begun to see the signs, but I didn't. I fitted it with a new Foxcon motherboard and new ram, also Kingston of 2 sticks of 512 Meg. Again I installed everything and burned it in with no hitches. 3 days later I got an email from him that the computer is unreliable and that nothing was working, especially Firefox and Thunderbird. I am beginning to suspect that there is a problem in the apartment they live in as far as power is concerned. What do you think?
Jim

Surge protection is very important and UPS also provide mains smoothing.

It may not be the power company power, but a misbehaving appliance. Fridges, kettles and tumble driers are well know for causing spikes within the house electrical system. Have a look at what is plugged into the same circuit.

There is also the possibility the spike is coming via the phone line (low probability but still possible). So whatever surge protection you get, make sure it deals with phones as well.

But if these are all in one apartment block, then it is cause for concern... if it can blow a pc, then other appliances will also be at risk. How you go about getting it checked depends on the ownership of the block.. but may be you should start with asking other people in the block about their pcs?

I know that I should go to their house, but I'm recovering from replacement of my right knee and have the left knee scheduled for April 25. My wife is epileptic and can't get a drivers license. Driving any distance is out of the question, and I don't know any family who I would trust to diagnose the problem. He lives in Huntington Beach CA. and I live in the high desert in Adelanto Ca. He has a desk lamp which has a screw in fluorescent bulb nest to his desk. I know that they generate considerable radio noise. I suppose that I will repair it for the second time and insist that he get a good UPS. I've been using a Belkin 750 Watt UPS for some years and it works great. I think that would be a good cvhoice for him.
Thanks for the suggestions, Much appreciated.
Jim

There is no reason why he can't ask his neighbours if their computers stop working recently is there? If he just gets one yes, it proves you are not to blame doesn't it?