Weird problem with my PC

[edsant]

Hello guys, first i want to thank you for the time you take to help us in the forums and chat. Many times i have been saved some bucks thanks to you.

I come here with a weird issue regarding my pc, and ill start from the beginning so please bare with me because its a long story and ill try to be as specific as possible.

It all started with a faulty sata HD with windows 7, the system would restart from out of the blue and bad sectors started to appear, i was told most likely it will be a faulty HD, so i contacted Western Digital explained the problem, and they agreed to replace my HD. In the meantime i started to use my backup IDE with windows XP as my primary HD. Everything went smoothly no restarts no nothing.

Then i received the replacement sata, so i plugged in both satas and the ide to the motherboard, on the bios i named the ide as primary hard drive, did a backup of the faulty sata into my external hard drive, and i was trying to restore said backup into the new sata, but i noticed there wasnt a letter asigned to it (like D: or F:), so i just formated it with the western digital formating sofware.

Next thing, i turned off my system, unplugged the defective sata from slot 1, plugged new sata into slot 1, took the defective sata, plugged back the machine, pressed the on button and then it started: the fans will turn on for 2 seconds and then will turn off for less than a second then on  for a couple of seconds and then off over and over again nonestop.

I started to troubleshoot the pc, went all the way i even did a breadboarding (i think its called like that) outside the pc case, in a wooden chair i would plug the CPU fan, the PSU, the on button, the front speaker, then it will turn on and will give me the beep codes, one long one 2 short ones, after that i can add everything into it, but the moment i add a memory, it will start again, you can plug everything back and it will turn on with the beep codes, just when adding the memories it will start with the on off on off. I have a backup PSU, brand new one and tried with it, same story.

Me im more inclined to say its the mobo that got fried, but i dont want to go buy a new mobo and then realize i just spent 150 for nothing. PSU works ok with everything plugged in, except when plugging a memory.

I checked every component, nothing smells like burned nothing looks burned, i was careful to discharge all the static energy and to press the on button when the machine was unplugged to discharge it.

The specifics of my PC are the following:

Mobo Asus P5b
Processor Intel Core Duo 1.8
Main PSU 575 W / Backup PSU 500w
Graphics ATI Radeon 5570
4 Memory Sticks 2x2gb Kingston 2x1gb Corsair
Sata 500GB AADS5000 WD Caviar Green
Ide 120GB

Thanks for your help and please let me know whatever info you need extra.

[Computer_Commando]

...I started to troubleshoot the pc, went all the way i even did a breadboarding (i think its called like that) outside the pc case, in a wooden chair i would plug the CPU fan, the PSU, the on button, the front speaker, then it will turn on and will give me the beep codes, one long one 2 short ones, after that i can add everything into it, but the moment i add a memory, it will start again, you can plug everything back and it will turn on with the beep codes, just when adding the memories it will start with the on off on off. I have a backup PSU, brand new one and tried with it, same story.
...PSU works ok with everything plugged in, except when plugging a memory.
...
Mobo Asus P5b
Processor Intel Core Duo 1.8
Main PSU 575 W / Backup PSU 500w
Graphics ATI Radeon 5570
4 Memory Sticks 2x2gb Kingston 2x1gb Corsair
Sata 500GB AADS5000 WD Caviar Green
Ide 120GB
...

Seems to indicate memory problem or video problem.
What is:  "one long one 2 short ones"?
http://www.computerhope.com/beep.htm
You didn't say if you had the keyboard & monitor plugged in.

[edsant]

If the keyboard and mouse are plugged or unplugged problem remains the same, the moment i add a memory it will do the turn on and off. I talked to one of your members and pointed me towards the capacitors, and i noticed that one of the capacitors was indeed bulged on the top. None of them where leaking tho, but this single capacitor was bulged.

The beep code indicates a video card problem, and just as an update, went all the way in and bought a new processor and a motherboard (200 bucks). Plugged everything in and it starts, just have to install everything back in.

Now regarding my question. Could the cause of my headache be that single bulged capacitor? and if so.. is it worth it to replace it? i mean i can assamble a new computer if i manage to make this mobo to run (already have all the components).

Thanks again for your help and time.

[patio]

Yes...
One bad capacitor will cause this...unless you have done soldering at board level i'd recommend a shop.
Too hot and you could brick the whole board.

[Computer_Commando]

Won't complete POST without a keyboard.

If bad cap looks like any of these, that could certainly be the problem.

Caps aren't expensive, if you can determine the value (i,e, ??uF @ ??VDC) & know how to desolder & solder.  Electrolytic Capacitors have polarity (plus & minus), put it in backwards & it will explode.

"...went all the way in and bought a new processor and a motherboard (200 bucks). Plugged everything in and it starts, just have to install everything back in..."
Does this mean all the other components are working?

[edsant]

I had to leave for work, but for starters the computer will boot. With the new mobo im able to enter to the BIOS. Will make a new post when i plug everything and finish setting up the bios.

The capacitor in question is bulged at the top altho no aparent leak, its just bulged like the one in the pic:

[Computer_Commando]

All 3 of those are bulged & are no longer functioning properly.  Read this:  http://en.wikipedia.org/wiki/Capacitor_plague

[edsant]

UPDATE:   Changed the capacitor and old mobo runs like a charm! yay! thanks guys for your help!