PSU replaced, computer still dead

[kaityf]

:( My son's computer died this morning. He tells me it has been making a kind of rattling noise for a while now on start up. Today, however, it wouldn't power up at all. I tried different power cords and outlets, but no go. I went out and bought a new PSU, installed it, and the computer is just as dead as it was this morning.

Is this thing completely unsalvageable? It is around 3 years old, but it's a homegrown computer. Someone built it for us. Is there something else I can check before I spend loads more money on this. Money I just don't have. We need a computer, but I don't want to throw money away.

Should I just take it in to the Geek Squad at Best Buy and let them figure it out or will I just end up paying more money than I need to. I guess I just need some ideas on what to check first.

I will be eternally thankful for any advice and suggestions anyone might have.

[pangea33]

BTW... Welcome!!

Did you ask him what he, or the computer itself, was doing right before it died? That could help with troubleshooting. Rattling could easily have been the hard drive on it's way out. Additionally, if there was a short somewhere, just about any component could have been burnt up. Take a look for the sticky on barebones troubleshooting a PC, step-by-step. I'll see if I can find it...think it's from Saphalline, but I am not sure.

[Jiggy]

Hi kaityf Welcome to PC Guide,

Try a barebones boot using only power supply, motherboard (out of the case on cardboard - and connect the power switch from front of case), one stick of memory/RAM, cpu+heatsink and graphic card,

Does it boot ?

If not then the problem is one of the above parts.

If it boots add back your parts one at a time rebooting after each part.

Does it boot ?

[pangea33]

Jiggy is offering the help you need, but I wanted to correct my mistake. Sylvander is the man who deserves credit for the great diagnostic flowcharts. Ernie K is hosting them too, if you wanted to have a look at the barebones guide or others: http://www.erniek.eclipse.co.uk/downloads/downloads.htm

[kaityf]

Thanks, everyone! I'll try the barebones thing, but I think I need a few days. I'm fairly computer literate, but not THAT literate. I know what the power supply is now that I've replaced it. And I'm guessing at the motherboard since that's where the biggest plug from the PSU goes. I think I know what the memory sticks look like. After that, I'm pretty clueless, particularly with the CPU + heatsink, but I can probably figure it out. Let me make sure I understand this, though. I should take the motherboard OUT of the case? Is that right? And if that works, add each of the other parts, one at a time? And if it doesn't work??? Does it mean that the problem is the motherboard?

I like tinkering with computers, but not with their guts. :eek:

My son said that nothing had happened out of the ordinary with his computer. I had heard the rattling sound, but it sounded like a really loud startup, but maybe it was a fautly fan?? He said he shut down the computer last night and all was well. I was hooking up my computer via a cable connection to a router that is hooked into another computer here. (I had been using a wireless connection.) I had gone to see if the wireless connection was still okay on my son's computer, and that's when it wouldn't come on.

I'll try to do this tomorrow night and then let you know what happens.

[pangea33]

I wonder how many times I told my parents that something was just fine when I last used it. Just kidding, that really can and does happen with computers. Startups are a little bit hard on a machine.

You've already changed the power supply, so you can't be too uncomfortable under the hood. You've got other machines too. Perhaps you could at least check a few components in it, such as the hard drive. Maybe the memory and video card too, if you feel up to it.

[beerbelly]

I like tinkering with computers, but not with their guts. :eek:
The stuff jiggy recommended isn't as hard as it may sound (being observant and gentle is the hardest part). As pangea33 said, if you're up to it the forums will help. This will involve getting inside the case with a screwdriver in hand, and removing/installing things. It all depends on your own comfort level.

[kaityf]

I was going to try Jiggy's suggestions tonight, but A) I'm too tired and don't want to fry the computer worse than it probably is already and B) I realized that I don't understand the directions. B may very well be related to A.

Anyway, I'd like to see if I understand the directions correctly. I should basically dismantle the computer. Take out the power supply and remove the mother board. The motherboard is the board where I plug in the memory sticks? And I use only one of them in this barebones startup. Is that right so far? I can figure out the video card easily enough, but can someone tell me what the CPU and heat sink look like? Are these attached to the motherboard? So when I do this startup, everything is basically outside of the case?

At this point I'm even more befuddled. Connect the power switch from the front of the computer? Of COURSE, there has to be a connection, but I don't remember connecting or DISconnecting anything from the power source to the power switch. Is it at all possible that this connection got loose? No, that's probably dumb.

I did one thing that I thought was safe in my state of fatigue-- I plugged in the old PSU to see what would happen, not attached to the computer, just all by its little self. Nothing happened. No fan, nothing but a faint, sad, sick little wheezing. So does that mean the PSU was definitely dead? And could my not remembering attaching the PSU to the power button be a sign of doing (or not doing) something stupid that accounts for the computer not starting up?


Thanks!

[saphalline]

Yes, the mobo (motherboard) is the biggest PCB in there. You can't mistake it because everything plugs into it. The RAM, the PSU, the drives, the expansion cards - everything! Mobo's are usually green, but it could also be red or black if you got an awesome mobo. ;)

The CPU & heatsink should be easy to spot. On the mobo, you should see a scary-looking metal thing with "fins" on it and a fan on top. If you see two of them, the CPU is under the largest one. For a barebones boot, you don't necessarily need to know where the CPU is because you won't be touching it, but it's nice to know where it is.

The PSU doesn't plug into the power switch directly, it all goes through the mobo. On a standard ATX mobo, the front case connections plug into an area on the bottom right (if you're looking directly into the case). There will be a bunch of colored wires all going to a 2 x 10 pin block. You should see them twisted in pairs, like green & white, red & white, etc. If you examine one of these by pulling it out (note exactly how it's plugged in) you'll see the wires go into a small black rectangle with writing on one side - such as "PWR LED". These are called "leads". As you unplug them, you should take detailed notes on which ones go where and in which direction. As you learn more about mobo's you'll be able to do this without taking notes, but for now take notes. In the fray of wires, you should see one labled "PWR" or "PWR SW" or something like that (usually green & white). This one is the power button. When you need to turn on a computer in an out-of-case barebones situation, you will need to short the two pins where the power switch lead plugs into the mobo. Just a quick half-second touch of the pins with a screwdriver will do. When you need to turn the system off, short the pins again by keeping the screwdriver there until the system shuts off. Most ATX mobo's default to holding the power button in for 4 seconds for a hard off.

It's not likely that a power switch lead would randomly come loose, but sometimes they do break. It's extremely rare, but it is possible.

Unless you know how to test a PSU with a multimeter, you can't simply plug it in and try to turn it on. Without a load on it, the PSU won't do much. They only draw as much power as is needed by the system, so if nothing is plugged into it nothing happens. If you live near a computer shop or a CompUSA, you can pop in and buy a PSU tester for $10-20. They are handy to have around, but the barebones test will determine if the PSU is the problem.

Anything else you need to know before doing a barebones test?

[jlreich]

Take look through Pete's sticky on component identification. http://www.pcguide.com/vb/showthread.php?t=25502

That will help you get familiar with the innards of your computer. :) It's a little outdated, but most things are basically the same. Well ok maybe you don't see very many dip switches anymore, :p but it helps a lot to get a grip on what's inside these things.

BTW Paleo Pete, ever consider doing an update to that sticky? Maybe some pics of PCIe slots, modern USB headers, SATA, 24pin power connector etc.. Oh and don't forget the cup of coffee. Gotta keep that in there. :D The sticky is still very valid as many system are still in use that have those components, but it would be nice to have some modern components in there as well.

[kaityf]

As you learn more about mobo's you'll be able to do this without taking notes, but for now take notes.

:D :D That's funny. "AS I learn more"??? Really, I wasn't planning on doing this too many more times.

Anything else you need to know before doing a barebones test?
Yeah. What's the phone number of the nearest Geek Squad?


I'll let you all know what happens tomorrow. Thanks again!!

[kaityf]

News from the dead computer front:

I confess that I was too intimidated by the prospect of removing the mobo from the case, so I thought I'd try something else first and see what would happen. That mobo is red and apparently awesome, so I was deathly afraid of destroying it.

I disconnected the power supply from everything except the mother board. I disconnected the cables from the CD drives, the hard drives, the floppy and zip drive. Everything else I left plugged into the mobo. It did power up, which is more than it did before.

Is that a good sign or did I have to have the hard drive plugged in too? I didn't see that in the list of things to plug in to the mobo, so I assumed I had to disconnect it, but then I started thinking that it can't technically boot up without an operating system, right? Or does boot up refer to power only? I always thought it meant starting the computer, including loading the system.

At least I'm feeling like I can see the breaking light of dawn after the dark dispair of the death of a computer.

[Jiggy]

Yes thats a good sign.

When it booted did you hear a beep(s) ?

Now it is booting when using the power supply, mobo, cpu+heatsink, one stick of memory and graphic card, start adding back your hard drives, cd-rom, floppy and any PCI cards one part at a time, rebooting after each part is added.

Does it still boot ?

It can boot up and POST (Power On Self Test) without the OS.

[kaityf]

Hoorah!

It all worked. I attached one drive at a time and rebooted each time. It worked every time. I don't understand why it wouldn't work when I first installed the PSU. I checked and double checked the connections to make sure they were snug and all in place.

Is it possible that the connection to the power button got loose somehow? I think I asked that before. I did push on the connections, both on the mobo and on the start button. I didn't notice that anything was loose.

Oh well. In any case, the dead computer is now revived!

Thanks a bunch everyone!!!

[Jiggy]

Good to hear, keep on learning. :)

[saphalline]

Sometimes I can check and double-check to my heart's content, but unplugging everything and plugging it back in is the only thing that works.

Congrats - first PC problem fixed! :D