Computer won't power up at all?

BlackScarletLove

Status:In Post-Production
Joined
6 Jul 2007
Messages
148
I'm pretty sure my cat screwed up my computer. I was in bed last night and the computer all of a sudden began making some really peculiar noises, and I woke up and turned on the light and the cat darted out from under the desk where my tower is and now it won't even turn on. Like, I press the power button and nothing whatsoever happens,as if it's not even connected to a power source. I checked all the connections inside and everything is connected just like it was before, but still no response to a power up.
I've never had a computer actually refuse to even power up before, at the very least it turns on but doesn't do anything -- this time it's totally dead. Does anyone know what could be causing this?

Windows XP SP3

AMD Radeon HD 6850 - 1024MB

MotherBoard:
ASUSTeK Computer INC. P5K SE Rev 1.xx
Bus Clock: 200 megahertz
BIOS: American Megatrends Inc. 0401 07/19/2007
Realtek Onboard Audio

3328 Megabytes DDR2 RAM

Processor:
2.00 gigahertz Intel Pentium Dual
64 kilobyte primary memory cache
1024 kilobyte secondary memory cache
 
Look for busted capacitor's, blacken connections, unplug and replug all of the connections, test the power supply without it being hooked to the motherboard or anything else, check the power cable between wall and tower, check the surge protector if you have one, the outlet in the wall with a light or something to make its still working.

Though my guess is the power supply failed, depending on the quality of it and it did fail it took the motherboard with it.
 
how would i test the power supply without it being hooked up?
and is there a possibility that the motherboard is fine if the psu failed?

i did disconnect the computer and checked all the connections, didn't see anything unusual, tried it on a working outlet and works fine -- the psu is an Antec, 530w, 36A. -- I thought this was a good one?
 
If you have a store like bestbuy or buying over the internet you can get a power supply tester from about 15 USD to 40 USD in the places I looked.

What I was wanting to know is does the fan in the power supply run when you turn on the system?

Yes depending on the quality of board used it could be just fine and by the same token it could be dead. Though Asus is a good brand, Antec from stuff I've read is kind of hit or miss on quality of late at least.

If its the motherboard you may be out of luck just getting a replacement, as the socket the cpu used is at least two generations old since I'm guessing its a socket 775, which means new cpu, motherboard memory, maybe video card not to mention a reload of the OS etc
 
Not even any of the lights come on on the motherboard, the psu fan doesn't work either, it's as if the thing isn't plugged in at all, no response from anything.

It would be kind of **** to have to get a full system upgrade -- that gpu isn't that old to me, I paid more for it than I want to pay replacing it so soon, and it's a pretty good gpu. But if I were to have to get an entire upgrade with the same functionality as the system i mentioned, any recommendations for brand and model of mobo, cpu, psu, etc?
 
Ok,dead PC debug-

You've done a bunch of the steps already so I'll skip those.

DIsconnect all the PSU outputs. On the big 20-24 pin MB connector there is a green wire next to a blk wire. Using Paper clip (bare metal one) or a peice of wire if you have one jumper the blk to the green wire. For most PSU thsi should cause the fan to spin up. If the PSU is a smart one with a thermal sensor the fan doesn't spin up when it is cold which is a pain since you can't check the PSU. IF it's a smart PSU you need a meter to measure the outputs Yellow is 12V orange is 3.3 and red is 5V. Measure from the color to a balck wire. The voltages may be higher since there is no load on the PSU. Lacking a meter if you have any 5V LED gadgets lying around hook it up from red to blk to see if at least the main 5V power is alive (just plug it into any accessory connector on the PSU).

If the PSU looks good kill power and hook up one part of the PC at a time and see if the PSu still comes up. I would do the MB last since it is the most likely failed component. Kill power before hooking up each new item. If the PSU works until you hook up the MB, pull the MB out of the case and lay it on some card baord, newspaper etc and try again. If the PSU comes up the MB is may have been shorting to the case. Reboot completely to make sure all is good. IF boot is ok time to figure out what was shorting. checking the MB fpads and case feet for proper alignment reinstall the MB. and try again.

If the PSU won't come up with the MB out of the case either the MB died (voltage regulator, burst capcitors as mentioned above, etc) or the CPU or RAM could be bad or misaligned and shorting something. Pull the RAM, try and power up,pull the CPU and try and power up. If still no joy it is probably the MB.

Good Luck.
 
Ok,dead PC debug-

You've done a bunch of the steps already so I'll skip those.

DIsconnect all the PSU outputs. On the big 20-24 pin MB connector there is a green wire next to a blk wire. Using Paper clip (bare metal one) or a peice of wire if you have one jumper the blk to the green wire. For most PSU thsi should cause the fan to spin up. If the PSU is a smart one with a thermal sensor the fan doesn't spin up when it is cold which is a pain since you can't check the PSU. IF it's a smart PSU you need a meter to measure the outputs Yellow is 12V orange is 3.3 and red is 5V. Measure from the color to a balck wire. The voltages may be higher since there is no load on the PSU. Lacking a meter if you have any 5V LED gadgets lying around hook it up from red to blk to see if at least the main 5V power is alive (just plug it into any accessory connector on the PSU).

If the PSU looks good kill power and hook up one part of the PC at a time and see if the PSu still comes up. I would do the MB last since it is the most likely failed component. Kill power before hooking up each new item. If the PSU works until you hook up the MB, pull the MB out of the case and lay it on some card baord, newspaper etc and try again. If the PSU comes up the MB is may have been shorting to the case. Reboot completely to make sure all is good. IF boot is ok time to figure out what was shorting. checking the MB fpads and case feet for proper alignment reinstall the MB. and try again.

If the PSU won't come up with the MB out of the case either the MB died (voltage regulator, burst capcitors as mentioned above, etc) or the CPU or RAM could be bad or misaligned and shorting something. Pull the RAM, try and power up,pull the CPU and try and power up. If still no joy it is probably the MB.

Good Luck.

Hey Lee,I'm afraid I didn't get far -- I disconnected all of the wires from the psu, and tried to power it up -- and just to be clear while I was messing with the wires, I had the pc plugged in with the main switch on the back set to 0 not 1, then when I was ready to power up I switched it to 1 and tried pushing the boot button on the front of the tower.

No results with all the wires out, and then I took a paper clip and bent it to put one end in the green wire and one end in the black wire, then flipped the main switch and the boot switch again, still nothing. So maybe this is a special psu? or maybe it's just totally dead?

I wasn't able to get farther than that, not having a volt meter and the only LED light i have is a 3V bike light and a ring light for a camera that plugs into a wall adapter and I don't know what to do with that.

I don't see anything wrong with the MB -- no burst capacitors or blackened anything -- everything looks just fine. I checked to see that the ram and cpu and gpu are all seated properly -- they are...
 
Well it sounds like the PSU is at the moment the most likely cause.

That said for brands I would go with OCZ, Thermaltake or Corsair and at least the same wattage as your current one that is at best questionable.

If that does solve the issue then good chance your looking at a new build
 
do you mean if it 'doesn't' solve the issue ill need a new build??

also im going to be getting my hands on a used psu to test with but chances are it's a lower wattage than the one i have -- would this be ok just to test with for a quick bootup but not to run with?
 
Does your motherboard have a power/reset button on it? If so try that, though thought you would have already did that.

Cause the if replacing the power supply doesn't solve it then its not the power supply and you already did the resetting of cpu, ram and other add in cards. You also ruled out the wall outlet.

Which leaves the components themselves and you can troubleshoot them but it becomes very time consuming cause you have to remove all of them then put them in one by one until you run into the problem provided the issue was resolved by removing the components to start with.
 
Ok so, I got a psu with the same wattage as my other one, and I plugged in the big 20-24 pin MB connector, and also the square 4-pin connection.
I couldn't plug in my hard drive because this psu doesn't have sata support, but I wanted to see if it would boot off the motherboard. I switched it on and the green light on the motherboard came on, which was a good sign, that wasn't happening before.

However, when I pressed the power button on the case, all that happened is every 4 seconds the cpu fan and the rear case fan spun for half a second and stopped, over and over again until I switched it off. No bootup. What does this mean? Did I just connect something wrong or is it a sign of something catastrophic?
 
OK the sata plug issue is minor, they make adapters for the psu's that don't have a sata plug on them.

However more troubling to me is the fact while it did power it never actually posted from it sounds like. Unlikely you hooked something up wrong though it is possible so might make sure everything both from the case to the motherboard and from the psu to the motherboard are hooked up correctly. If so that leaves the motherboard itself as having a problem. There could be something bridging things on the underside of the motherboard though that seems unlikely.
 
Have reset the battery in the motherboard and plugged in the two leads from the gpu, great news is that it boots up now, or at least it starts up and beeps like normal; I have not attached a monitor to it yet, mainly because the tower is all in pieces on my table and my monitor requires me to have the tower under my desk. That is a lot of work, and with this power supply I have no sata support so can't plug in C drive, so I want the system to have the potential to be functional before I put it all back together and put it back under my desk.

Also, I notice that this psu has detachable leads,
(similar to this although this is not my actual psu)
p3s.jpg


and I wonder how common the lead wires are that i might be able to find one with sata connectors for cheaper than buying a whole new psu? not to mention that if there is something else wrong with it i'd want to know before I go purchasing any actual major components
 
Well maybe it was a issue in the BIOS/CMOS that was the issue as the fact resetting the CMOS battery fixed that.

I find it odd that the new power supply didn't come with a sata power connector since sata drives are more common then old ide/pata drives but thats me.

You might be able to get one at your choice of store locally but here is a link to fix the issue of not being able to hook up your sata drive to the power supply
Newegg.com - SYBA Model SY-CAB40046 5" Molex 4-pin to SATA HD Power Connector Cable - SATA / eSATA Cables
 
the new supply is actually an old supply lol, i got it out of an old tower in someone's basement. looks like a good one though, antec 500w, i picked up a coverter today
 
Well, sort of good news, but overall bad news, i plugged in the power supply and hooked everything up including the system drive and monitor and turned it on and I got the initial splash screen that says "Press DEL to run Setup, Press TAB to display BIO|s POST Message"

And it just froze there, so I pressed DEL, then TAB, but neither of them would work. So for whatever reason it's not allowing me past that stage. I know the keyboard is plugged in properly, because the lights come on and respond to caps lock, etc.

What's wrong now?
 
Well might try it without the drive hooked up, otherwise remove anything not needed to get to POST and see if you can access the BIOS.

Thats pretty much lets left to try is take down to the least number of components try and depending on that result add one component back at a time until you run into a problem.

Though it appears that whatever the issue is seems to be the motherboard itself but can't rule out anything else yet
 
If that PSU is too old it might be missing connections to the MB that new systems require.

Also, it is not just the wattage, the amperage rating on each output (especially 12, 5, 3.3) is critical on new systems. But at post it's less likely the issue. Compare anyway.

Old PSU might be 12V@10A, 5V@30A3.3V@14A.
New PSU will be 12V @18-30A, and have multiple 12V outputs. The 5V and 3.3V will be lower on the new PSUs.
New systems down convert the 12V to precisely what they need on the MB and Vid cards for better performance.



Like Chastity said. Pull out all non essentials just to see if it runs POST with less load on the PSU.
i.e. no drives, only 1 stick ram.
 

Members online

No members online now.

Latest profile posts

Also Hi EP and people. I found this place again while looking through a oooollllllldddd backup. I have filled over 10TB and was looking at my collection of antiques. Any bids on the 500Mhz Win 95 fix?
Any of the SP crew still out there?
Xie wrote on Electronic Punk's profile.
Impressed you have kept this alive this long EP! So many sites have come and gone. :(

Just did some crude math and I apparently joined almost 18yrs ago, how is that possible???
hello peeps... is been some time since i last came here.
Electronic Punk wrote on Sazar's profile.
Rest in peace my friend, been trying to find you and finally did in the worst way imaginable.

Forum statistics

Threads
62,015
Messages
673,494
Members
5,621
Latest member
naeemsafi
Back