PC Repair help

Hi guys,

I've got a 1.8 ghz athlon PC here that I'm attempting to bring back to life. This machine was rather negelcted for a while and was used by (shudder), children.

The problem is that the computer turns on when I press power, however the monitor gets no signal. The monitor shows that same message it does when not connected to a PC and turned on. I opened it up and checked the video card -- its connections and everything else seemed fine there.

When i hit the switch, the machine turns on and all the mobo fans are spinning, but there are no beeps. I don't hear any activity from the hard drive either other than right when i press power. Don't really know where to go from here.

Its a pretty standard computer. Athlon XP, ~768mb ram, geforce vid card, Win XP. It worked great back in the day, I just havn't touched it for a while and recently found a new use for it. Any tips?

First thing to do is pull every card, including the video card, out of the computer, and disconnect every cable to the motherboard except for the power connection.

Then power up the system. If you hear beeps, look up the beep codes in the motherboard's manual (look online for the manual if you don't have a dead tree version).

If you don't hear beeps, scrounge an old "known-good" video card (a different one from the one that's in the system) and see if you can get it to boot that way.

If that doesn't work, you're looking at a bad mobo, bad CPU, or a bad power supply. If it were bad RAM, I'd expect to hear beeps.

Do what Tony says.

If that's not a goer, you could pull the RAM too. You have 768MB so there's at least 2 sticks in there. Pull it all out. If it then powers on with something beeping (probably long beeps), try the RAM one at a time.

Is the monitor saying cable disconnected or no signal? My monitor seems to be able to tell the difference between "plugged in and PC off" and unplugged.

If the children who used it were the knowledgable type, there could be problems with the BIOS or CMOS (ie: they tried to overclock it or something). Resetting the CMOS jumper (following the instructions in the manual) may help.

Also, I've had machines fail to POST (power on self test; the first beep you hear) because the memory wasn't pressed in all the way. After installing RAM, I give it a firm press on the center of the thin edge, making sure it's in.

If all else fails, blame it on bad IDE headers and send it for repair.

Oo. Good point about the overclocking and BIOS settings. Yeah, find the motherboard manual and locate the CMOS reset jumper.

Does the monitor work on another PC?

My other thought would be a bad power supply.

Rene

Oh yeah, good point. Are you sure the monitor is even any good? Or its cable? I've had monitors where the cable went bad or the pins on the connector got bent.

I administer or help out with only a very small number of machines (less than a dozen) of various makes in various location. In the last 12 months, I've seen a total of 4 of these machines have their power supplies get reclassified Tango Uniform. The last one (2 weeks ago) was the very exact symptoms described here. Based solely on my experience, my money's on bad power supply.

Yeah, that's highly likely.

Another thing to worry about: In my first reply in this thread, when I mentioned bad mobo, cpu, or powersupply, I neglected to mention the times I've seen a bad power supply make the motherboard or CPU go bad. So you might (correctly) replace a failed power supply only to find that the mobo is bad.

Multiple simultaneous failures are always a bitch.

Like adavidw, I administer 30 machines and have five powersupplies which "failed" in the last, oh, 6 months. But they didn't fail, they simply overhead because their CRAP "sleeve" fans get dusty and die. Once I figure out how to solder, I'll swap those fans out for double ball bearing Antec fans and put the PSU's back in service.

I wouldn't think it's a bad cpu or motherboard. In the past 15 years, I've probably only seen three bad motherboard and one bad cpu. One motherboard's problem was inexplicable, one motherboard had physical damage, as did the other motherboard/cpu combo (thanks to me trying to install at 2am the heatsink which was CLEARLY designed to be as unergonomic as possible... requiring proprietary tools to install?)

Bad ram, maybe. I had an Abit motherboard that burnt out its own ram chips. Turned out, Abit decided to "speed boost" their ram by increasing the voltage higher than usual by default. After a year, the mid-grade ram was toast (though my machine is the same Abit, and the registered DDR chips have survived for years).

For a machine that sat idle, there's even a tiny chance the motherboard battery is dead. I've had machines which won't POST without it. Good luck.