computer wont turn on

[sarcasticone]

I've had relatively few problems with either of my computers since I built them a couple years ago. Well, the spare computer is now acting up and I'm not sure of the problem.

It was working fine on Monday and then yesterday it wont turn on, sorta. My girls brother went to use it and pressed the power button to it on, but the monitor didn't turn on he said. So he calls me at work to let me know, I tell him to double check the wires and make sure it's all plugged in which he confirms it is. So then I ask him to pres the restart button on the front of the tower, he says nothing is h happening. I ask him if it sounds like it's restarting and he said it didn't change. So I ask him to hold the power button in until the computer turns off, he held it for about a minute and nothing happened. So I had him switch it off and wait til I got home from work.

As soon as I switched it back on the computer came on but only did what it was doing before, which when I normally plug it back it the fans and lights turn on for a quick second then turn off. But now it just turns on. I tried listening for the hard drive to spin which I dont think it is. The keyboard doesn't have power, the CD-rom's wont open and the monitor doesn't get a signal from the computer. But the fans are spinning and that like it's running. Also, after I turned it on and off (by switching the power on the back) I thought I could smell a burnt smell, but I never smelled it after that so I dont know. I couldn't see anything that looked obviously burned or looked like it had arced.

I have a spare PSU so I went and swapped the PSU and tried it again, same thing though. So I dont think it's the PSU. Any other thoughts on what it could be?

Thanks

 

[robisbell]

check yo make sure everything is seated and plugged in securely, sounds more like a power surge took the board, but will know one you've reaseated all the card, memory, processor, and power plugs.

 

[sarcasticone]

hmm... I guess. I would figure the surge protector should have prevented that though, or am I mistaken?

I will give re-seating everything a shot. But just out of curiosity what would re-seating everything do? I mean, what would happen to them to requiring them to be re-seated? It wasn't like the computer was dropped or something. Not doubting, just wondering, I'm more familiar with cars.

Thanks for the suggestion, will give it a try tonight.

 

[robisbell]

well, sometimes the vibarate out of the slots over time, this is a tower case right?

 

[corkyg]

Make sure the CPU and cooler are properly seated. Now and then they can vibrate loose, and a failure to start, POST, etc., is a result. If memory is bad, you will usually get warning beeps.

 

[sarcasticone]

Originally posted by: robisbell
well, sometimes the vibarate out of the slots over time, this is a tower case right?

yes, it is a desktop (tower) setup.

ok, didn't realize that.

 

[sarcasticone]

Originally posted by: corkyg
Make sure the CPU and cooler are properly seated. Now and then they can vibrate loose, and a failure to start, POST, etc., is a result. If memory is bad, you will usually get warning beeps.

I will go ahead and re-seat everything tonight and give it a shot. I should still have a tube or two of AS5 thermal grease.

I can't recall hearing any beeps, but I will make sure I double check and listen for that as well.

Thanks

 

[robisbell]

as for the cpu and hsf. make sure you thoroughly clean them both and you only need a dab of the compound. reinspect all the hardware internally, and also make sure he did not accidentally switch the psu to 220.

 

[amdskip]

Look at the motherboard and see if any of the capacitors appear to be pushing their guts out.

 

[sarcasticone]

Originally posted by: robisbell
as for the cpu and hsf. make sure you thoroughly clean them both and you only need a dab of the compound. reinspect all the hardware internally, and also make sure he did not accidentally switch the psu to 220.

yeah, I have some cleaner and that if I remember correct. I use a coffee filter to clean it since it's lint free. And I only use about a grain of rice size of the thermal grease.

I didn't think to look at the 115/220 switch but I don't think he did that since it's recessed down and harder to switch by accident. But it's something to double check. I do know the PSU I tried out was switched to 115.

 

[sarcasticone]

Originally posted by: amdskip
Look at the motherboard and see if any of the capacitors appear to be pushing their guts out.

I did look for that after I thought I smelled something burnt but I couldn't see anything out of the ordinary. When I take everything out to re-seat it I will be sure to check over the board and see if I notice anything.

Say I don't see anything like that, does that mean the board is fine or does it just mean it could be something else on the board thats wrong?

 

[robisbell]

you can use qtips too, and I use a 50% alcohol solution to clean both and then let them dry and a cloth to wipe of any residue before applying the new paste. I think a bit more than a rice size will be needed, hard to explain what a dab of it looks like.

 

[sarcasticone]

yeah, I have the ArtiClean Thermal Material Remover and ArctiClean Thermal Surface Purifier. I know what you mean though, I just follow the instructions on the arctic silver website.

 

[sarcasticone]

well, I just got done pulling everything and re-seating it all. I cleaned both the CPU and heatsink, pulled and re-seated the CPU, pulled the video card, pulled the memory, etc and re-seated it all and still the same thing.

What has me confused is why is it that as soon as I flip the power switch on to the computer it powers on without having to press the power button. The power and reset buttons do nothing. I dont hear any beeps when I flip the power switch on either.

I also looked over the board and didn't see anything that would indicate a part fried itself.

I'm not sure, any thoughts?

 

[robisbell]

check all the capacitors to make sure none are swelled up, i'd pull the front panel wires off and try powering it up with a jumper.

the last resort would be to pull it out of the case and try booting it up outside of it. you may want to check the PSU's voltages as well.

 

[sarcasticone]

I didn't see any capacitors that appeared to have burst or swelled.

I did try pulling the power switch wires of the board and it still did the same thing. What should I use as a jumper? And am I only supposed to jump the power switch? Not like I need a reset switch or the power/hdd leds.

What terminals on the plug should I be checking for the voltage? I dont think it'll be this since I tried another psu but it's worth a check.

 

[practor]

New MoBo

 

[robisbell]

http://www.devhardware.com/for...-it-to-test-75111.html

http://www.metacafe.com/watch/...ters_power_supply_psu/

 

[sarcasticone]

ok, I will give that a shot and see what I find.

 

[Shwag]

I have the exact same problem as your having. Plus my keyboard lights dance.
However, I believe I narrowed it down after frying 3 motherboards.

I had a nice socket 478 system a couple years ago, overclocked, nice ram, good video card, ect ect... One day I couldnt get it to start and figured the power supply was cooked, so I went and bought a new power supply. Antec 500W. Got home and installed it, now the computer wouldnt even post.

I set up a different computer for a while and ordered a new motherboard. The mobo came and I assembled everything, same thing happens.

Since then(about a year go), I have been using the same computer I set up temporarily.

Today I was home sick so I decided to swap the guts of the temporary computer into the case of the broken computer since it looks much better. The only thing I didnt take out of the case is the Antec power supply I went and bought at the store. Bam, there goes my temporary computer as well.

So after doing that, I tried all three of the motherboards and none of them work with a known working power supply. Shucks.

 

[Old Hippie]

Originally posted by: robisbell
http://www.devhardware.com/for...-it-to-test-75111.html

http://www.metacafe.com/watch/...ters_power_supply_psu/

Coupla nice links. Even I probably couldn't screw-up with those! :thumbsup:
On the other hand, I've screwed-up a couple of two car parades.

 

[sarcasticone]

hmm... yeah I haven't gotten a chance to test my power supply yet. Been busy doing some work to the house (getting more insulation in) and now I'm about to start working on my car. So probably after I'm done with my car and probably after the holidays at that point I can get around to checking the power supply. I'm not really motivated right now anyway cause I'm not putting any money into it until I'm done with my car. Then I'll probably upgrade my other computer and swap everything else into the broken computer.

 

[sarcasticone]

ok, so I know it's been months since I started this thread looking for answers. I've been busy with a big project with my car and just haven't had time to really sit down and start working on the computer. It being a second computer doesn't exactly drive me to get it fixed either. Anyways...

I was reading and watching the video linked on checking the PSU as well as reading some others as well. They say to check with the computer running so I could check the voltage at certain points of the computer starting up and running. I can't do that because my computer doesn't boot. The other test is to do it with a paper clip or wire jumped between the green and black wire in the 20 pin connector, connecting a fan and seeing if the fan powers up. I assume the PSU will pass that test since the case fans on my computer come on but the computer just doesn't post or anything. At the end of the video it says something about if the case fans come on but your computer still doesn't boot up they will address that in their next tutorial but I couldn't locate that anywhere.

So should I just plug in my computer and let it run as is to do the test with the multimeter? See if I am getting the proper voltage to the wires they have specified but instead of recording it through each step of boot up just do it at it's current state of whatever?

Is there a way of testing the PSU out of the case for proper voltage? Would this be jumpering the green and black wires with something running like a fan to test for the voltage on the 3.3v, 5v and 12v?

 

[Dream Operator]

Even if you get power and fans spin up, a PSU can still be bad. It happened to me a couple of years ago. My PC won't boot right now, blank screen after installing second video card for SLI (separate topic for all that!!). I used a PSU tester by Antec to check the status. My PSU tested good.

http://www.newegg.com/Product/...x?Item=N82E16899129001

Does it still power on when you turn the PSU on? My friends PC was doing the same thing last week. The connector for the power button was on backwards on the motherboard.

 

[sarcasticone]

if I recall correctly I tried pulling the wires for the power plug and it didn't change anything. I will try that again though just to be sure. But when I plug in the PSU and flip the switch on the back to give the PSU power, it just starts running. Usually when you do that it will turn on the fans for a split second and then nothing, well now it just starts and the only way to turn it off is by flipping that switch on the back or pulling the plug.

I will have to see if I can find a PSU tester locally, if not I will go ahead and order one.