Computer only sometimes powers on, sometimes doesn't

Our relatives gave us an old computer to use for our kids. It's an IBM NetVista.

Problem is the machine only sometimes powers on. It's either/or. Sometimes it will boot up to Windows XP just fine, with no weird noises or hums or beep messages or anything. Runs beautifully. Other times it's completely inert, no lights, no attempt to power on. This occurs without me touching the machine at all.

It seems to be more likely to power on if I leave it alone for a while; however, I have never had the machine on longer than a minute or two, so I don't think it's overheating.

I've swapped out the power cable, but this still happens. I've opened the box and all cables seem to be seated correctly. It was one RAM stick which is seated firmly, and like I said, sometimes it powers on.

Is this a problem with the power supply then?

Chris

 

Some machines seem to really need a good CMOS battery to boot properly although most boot fine with a bad one but just give an error about having lost some basic time/date settings. I had an old Dell that needed a fresh CMOS battery or else I had similar symptoms to yours. Before replacing the power supply I would try a new battery.

Batteries are available at most big drugstores/supermarkets or Radio Shack for under $5. You can check the number on your battery but most are the same as the pic CR2032 type.

http://pctechnotes.com/wp-content/uploads/2009/09/cmos_battery1.jpg

 

You could also try it with nothing connected - just the motherboard - remove the RAM, the CPU and the power supply, and see if you get a response (should be some beeping and lights).
Does the Mobo have a light on it?
I have vague memories of odd behaviour if the CPU fan isn't connected (in which case you might have a poor connection). I can't remember if it stops anything from happening. Can anyone comment on that?

 

:confused Umm, Err, how are you going to get any lights if you remove the power supply?

"remove the RAM, the CPU and the power supply, and see if you get a response (should be some beeping and lights). "

 

Thanks! This did the trick! I got a $5 CR2032, popped it in, and everything's fine now.

Something I should've caught before: on bootup the system would say it didn't have the date and time set. I don't know, I guess I assumed it's because it was an old unused system...but that makes sense now.

Chris

 

Glad it was something simple.

Yeah, the battery keeps track of basic configuration settings. When the system is unplugged it draws more power from the battery, so unused systems tend to chew up the battery. You should be good for a couple of years even with periods of non-use.

 

Glad it's fixed.
Just for the record, what I meant was, try it with nothing connected - just the motherboard (remove the RAM), the CPU and the power supply. The brackets make it a bit more sensible - hopefully.