My roommate has a Compaq SR1120NX that he says suddenly made a popping or snapping sound ~10 minutes after booting into Windows for the first time in a while, then wouldn't power up at all. He says he talked to someone at BestBuy and they said it is the motherboard but my guess was the PSU. I had never heard of anything going wrong with a computer and it being noisy besides maybe a CD exploding.
From a quick search it seems like if it is the mobo, you can't just replace that in brand name computers since they are proprietary. I was thinking that a PSU would be replaceable however. I found one thread with a possible solution, unplugging the CMOS battery and power supply cables, but kind of don't understand how to do that or where these are. Thanks if anyone can help. This is the thread http://www.tomshardware.com/forum/197086-28-help-turn
The one thing that usually audibly pops is one of the big capacitors in the PSU. You can only confirm that if you open the thing up. (If you are lucky you can see the damage from the outsinde). The way I would fix this problem is to take one of them cheap PSU testers and see if it's gone. You'll most likely have to replace it. I hope it didn't take the MB along with it...
I opened it up to look for some sort of blast zone but didn't see anything. Maybe I will try taking the PSU out completely and look. I ought to be able to help him find a fairly cheap PSU and just replace it right? (they aren't proprietary like mobos?)
I would agree that a capacitor in the PSU could make a popping sound and therefore be bad. The PSU is easy to replace. It might be possible to replace the motherboard with a cheap one from Newegg. Not all OEMs use proprietary motherboards. On the other hand, if teh motherbaord also needs to be replaced and money allows, your roommate might be able to pick up a new copy of a Windows OS and reload from scratch, thereby removing the problem of an OEM OS not accepting a new motherboard. With a new motherboard, he could then advance to using a PCI-e graphics card if he ever wanted.
If it's the power supply, don't replace with anything too cheap, or you'll risk this same problem. Go with a good manufacturer: Corsair, PC Power and Cooling, Enermax, Antec, Silverstone. You should be able to find a good PSU for $50 with reasonable wattage.
Do you guys know if there is some motherboard that works with this particular model? I really don't know offhand how to find that out.
I also don't know how to find out if it is the PSU or both the PSU and motherboard, without telling him to buy a new PSU and hope the motherboard works.
I know he is really on a shoestring budget and might go for a PSU on newegg that was listed $40 + $20 MIRB, its that bad... Maybe he should just get a new PSU, test it and if the mobo is bad as well, get a new motherboard. Hopefully the hard drive/RAM and such is still good.
Can you typically fit any old motherboard into a Compaq case if that needs replaced too? If not I might tell him to try to find a free computer on craigslist and try to help him piece something together.
But I would not be taking that psu apart. If you don't know what you are doing, those things can give you a nasty zap if you touch the wrong part.
Hopefully one would remember to unplug the power supply at both ends before disassembling it.
To the OP: It sounds most likely that your PSU burned out. The unfortunate thing is that when it fried, it could quite possibly have also shorted out anything else installed in the PC. Only way to find out though, is to replace one piece at a time until the system works again. I'd start with the PSU obviously...