PC Stopped working

[jiewmeng]

need help diagnosing whats wrong with ny PC.

* no bios screen on startup, no display at all, no beeps either

* when i poer the PC, the CPU and GPU fans where spinnning but the LED for the power button is not lit.

* recently, 1 RAM module failed and it was removed so RAM 2GB now, down from 4GB DDR3 1333

[Guest]

Remove all but one RAM module and test each module individually. If the results are the same then you can rule out the RAM since it's not likely that all RAM modules went bad at once.

Find a spare CPU that you can swap and test each. If no change then you can rule out the processor.

Find a spare video card to swap and test. You should know the drill by now.

Swap the power supply and test again.

If you haven't found the cause after all previous testing then you probably have a bad motherboard.

Notes:

• Check all cabling and connections each and every time. It won't turn on if it's not plugged in!
  
• Look for obvious physical damage. Test visibly damaged parts FIRST.
  
• Keep your spare and obsolete parts. You'll never know when they'll come in handy for testing.

Edited June 21, 2010 by 5eraph

[cluberti]

Usually when a system won't even post (but fans spin up), I've always found it's one of 3 things: one, the CPU itself, two, the seating of the RAM, or three, you probably don't have enough juice going to the system from the PSU to power it up.

[mammoharram]

I already faced a problem like this before 2 times.

First time. It was a Dell laptop, when I pressed the start button, It gave me the dell logo then a black screen ... can't go to windows or even to Bios .. no F2 no del no options at all. I just removed the external Battery and the Bios Battery as well, and then I turned the Laptop on ...Then the laptop works and still working very well . (don't forget to return the Bios battery back to it's place). B)

Second time. It was a Desktop PC ..when I turned it on, nothing but the CPU fan operated, even the monitor there wasn't any signal. I tried every thing you can imagine, I replaced every part of the computer to test it except the motherboard, unfortunately nothing happened.

Something may helps you to know if the motherboard is bad or not, As I did in my case, Is to remove the CPU fan then start the PC and put your finger on the CPU and notice if the CPU temperature increases or not, If not, This means that there is not enough power going to the CPU to wake it up. so you have to replace the motherboard, this is what happened with my fiend's PC .

NOTE:

If the CPU temperature increased(this is the normal and should happen in any computer), you should immediately unplug the power cable(cut the power) to save the CPU from burning , and then return the CPU fan back.

Thats all

I hope it helps

Good luck

Edited July 24, 2010 by mammoharram

[bonestonne]

Take the computer apart and do a test bench setup by putting the motherboard on a piece of cardboard and having the power supply connected to only what is absolutely needed, ATX, P4 connector, and graphics if needed. Use a screwdriver to short out the power on jumper. If the computer works like this, the case is at fault by causing a short circuit or not having proper grounding.

I've seen computers that work perfectly fine with a test bench but will absolutely refuse to work inside a case. This is generally caused by hairline fractures on the board, generally caused by mishandling or even shipping. You'd be surprised how poorly some boxes are treated during the handling process, or even manufacturing packaging process.