Parents' computer won't POST

UncleSporky

This is a few-years-old HP desktop running Windows XP with all updates, generally virus/spyware free but perpetually somewhat slow due to parental use, lots of startup programs and the thing is basically always on.

The power supply in this computer died at least a year ago, and we bought a new Antec power supply for it which worked great.

Stock RAM was only 512 which sucked, but they lived with it for a long time. We put in 2 gig in the last 6 months or so.

About 2 weeks ago, the computer randomly turned off when they weren't doing anything with it, it was just sitting at the desktop. It wouldn't turn back on again right away, it was getting power but wasn't POSTing. They let it sit overnight and it worked again the next day.

A few days ago when Age of Empires 3 was on sale for 10 cents (pretty nice), I got it for my sister and installed it on their computer. As I was trying to run it, the computer turned off again. It turned back on with no trouble and AoE3 worked fine.

Then yesterday it shut off again for my mom in the middle of a game and wouldn't turn back on. I was told that just before it turned off it looked like all the colors on the screen were fuzzy, and I don't really know how to interpret that. My mom also thinks she heard a pop somewhere from the middle of the computer, but didn't smell anything.

I looked at it today. It powers up, fans spin, DVD drive opens, but we get no video or beeps. I took out the 2G RAM and put the old RAM in, nothing. Tried it with no RAM at all, nothing. Num lock and caps lock don't trigger their lights on the keyboard either.

Nothing looks blackened or broken inside. I was pulling out the heat sink and the CPU came with it, right out of the socket, but I've seen that happen before and been fine. It wasn't really stuck too tight to the heat sink and it didn't look fried on the outside at least. Reseating it didn't help.

I am left guessing between the PSU and the motherboard, or perhaps I was wrong about something else. Based on this information, which do you think is more likely to be the problem? Which should we replace first, in the interest of not wasting too much time or money? I don't have any spares on hand to test with.

Do you think the first PSU death could've weakened the motherboard and it just took a dump? Or was the first death symptomatic of power issues at my parents' house and this second PSU is now dead from the same causes?

Thanatos

You know, it's the Christmas season, and everything is on sale. Honestly, you're probably best off going to Wal-Mart, picking up the cheapest Windows 7 desktop they have there, and replacing your parents' computer with that.

Trying to repair a several-years-old computer is probably just going to be a waste of time and money, and you're going to get a low return even if you do manage to replace whatever is broken (I would guess mobo).

Viscountalpha

UncleSporky wrote: »

This is a few-years-old HP desktop

First of all, it could easily be a cooling issue. The powering off is the cpu possibly overheating. Second Why not build them a new computer?

http://www.newegg.com/Product/ComboBundleDetails.aspx?ItemList=Combo.513430&cm_mmc=BFUS-_-SuperCombo-_-513430&nm_mc=BFUS

I'm not an amd fan myself but that's a decent looking start for a reasonable price.

Also, Avoid premade pc's. Far too many of them use sub-par components or proprietary designs. Avoid them!

Thanatos

Viscountalpha wrote: »

UncleSporky wrote: »

This is a few-years-old HP desktop

First of all, it could easily be a cooling issue. The powering off is the cpu possibly overheating. Second Why not build them a new computer?

http://www.newegg.com/Product/ComboBundleDetails.aspx?ItemList=Combo.513430&cm_mmc=BFUS-_-SuperCombo-_-513430&nm_mc=BFUS

I'm not an amd fan myself but that's a decent looking start for a reasonable price.

Also, Avoid premade pc's. Far too many of them use sub-par components or proprietary designs. Avoid them!

Even if he were buying it for himself, I wouldn't agree, but it's for his parents; they're going to use it for a little net-surfing, e-mail, and maybe some Office stuff; why bother building them something custom when you can get something comparable that's way easier to deal with from Costco for around the same price?

And if it were the CPU overheating, it would probably at least post; it doesn't. So, if it was the CPU overheating, it's probably fried.

UncleSporky

Thanks Thanatos, I was leaning in that direction. It's probably not overheating because as you say, it's been given time to cool off and ought to at least POST.

My dad looked up instructions online and tested the power supply with a multimeter, and says it comes up fine. I've never tried anything like that, so I don't know if that's a good indicator or not.

It's probably the motherboard. Money is tight, dad's not willing to get another computer right now, so we'll probably drop the $90 to get a replacement. Hopefully it's what we need.

Henroid

It could just be the battery on the motherboard.

yellowdart2

Just throwing this out there, but a PC usually doesn't post if the CPU isn't locked in it's slot. Did you actually lock it, or did you just put it back in?

Hugh Jass

UncleSporky wrote: »

Thanks Thanatos, I was leaning in that direction. It's probably not overheating because as you say, it's been given time to cool off and ought to at least POST.

My dad looked up instructions online and tested the power supply with a multimeter, and says it comes up fine. I've never tried anything like that, so I don't know if that's a good indicator or not.

It's probably the motherboard. Money is tight, dad's not willing to get another computer right now, so we'll probably drop the $90 to get a replacement. Hopefully it's what we need.

Just a thought but did you disconnect/remove all non-essential devices (Cd-Rom, NIC, Modem etc.) and then try to power it up? I ask because sometimes a dead PCI card or other device can cause the whole system not to boot. I once removed a dead modem in a PC that couldn't POST and wala it booted just fine. Its not very likely to be your problem, but its a good idea to check just in case. Also a good way to determine if a board has died, is to check for puffy or pushed up capacitors.

Oh and also, do you hear the system beep when you turn it on or when you removed the ram? If you turn on a system without ram they usually beep if the motherboard isn't dead.

StrifeRaZoR

Well, there's one outrageously off the wall solution that I can throw out there. And it's only due to the fact that I've experienced it before. PSU checks out. Doesn't POST with RAM or without RAM. All devices are getting power. Keyboard isn't lighting up and you're getting no video. Hear me out here:

Motherboard isn't grounded.

I know, I know. Crazy diagnosis. Happened to me. The motherboard in my current system had been jarred just a bit so that some of the circuits near the back I/O panel were actually touching the panel. After removing the board and booting it outside the case, it worked fine. Put it back in, it worked fine...for a while. I had to shave off some of the metal on my back I/O panel to get the thing to work 100% of the time.

Just throwing that out there.

UncleSporky

Henroid wrote: »

It could just be the battery on the motherboard.

Wouldn't that usually come up with a message that the battery is dead or missing? I've taken out batteries and got feedback before. Guess that's one thing I haven't tried yet.

yellowdart2 wrote: »

Just throwing this out there, but a PC usually doesn't post if the CPU isn't locked in it's slot. Did you actually lock it, or did you just put it back in?

Yes. It was locked in its socket, and actually pulled right out of the lock as I pulled on the heat sink, but as I said that's happened to me before. It doesn't seem like the modern ZIF socket locks too well. But yes, I pulled back the tiny lever, set it back in, locked it down and pulled a bit to make sure it was secure. There were no bent pins or anything despite pulling out.

Hugh Jass wrote: »

Just a thought but did you disconnect/remove all non-essential devices (Cd-Rom, NIC, Modem etc.) and then try to power it up? I ask because sometimes a dead PCI card or other device can cause the whole system not to boot. I once removed a dead modem in a PC that couldn't POST and wala it booted just fine. Its not very likely to be your problem, but its a good idea to check just in case. Also a good way to determine if a board has died, is to check for puffy or pushed up capacitors.

Oh and also, do you hear the system beep when you turn it on or when you removed the ram? If you turn on a system without ram they usually beep if the motherboard isn't dead.

No, you're right, I have yet to do this. In the interest of thoroughness I ought to, I make too many assumptions sometimes.

The system never beeps, with or without RAM, and it's not a case of an unplugged PC speaker or anything because it used to always beep on startup as it should.

And I'll check that too StrifeRaZoR, though it'd be strange for that to suddenly happen without having moved/modified the computer in half a year. I guess it could've been bumped the wrong way...

StrifeRaZoR

Computers are pretty finicky lol. I was just throwing it out there. The odds of it being an ungrounded board are slim to none.

But yeah, good luck with it. And don't pull out too much hair over it