No power

[seafrog3]

My son brought his computer over for me to fix. He had, had a power surge during this last storm and the computer quit working (was plugged into a surge protector power strip). No light on motherboard when turned on. Figured it was the power supply. Installed a new one.

Now the red board light comes on. The fans (case, chip, etc.) start up and the blue LED lights come on. This lasts about 4-5 seconds. Then everything goes dead. No red MB light, fan or anything. No time for the motherboard beeps or anything.

I disconnected the case fans and CD/DVD drives in case they were pulling too much power (it would not stay on long enough to get warm, let alone HOT).

Cleaned out dust bunnies the size of mice (vacumed and blew out dust). I re-set the boards, etc.

Further info: Home assembled computer, ABIT NF7 MB, Athelon chip, Kingston memory, WD hard drives, etc.

Please tell me what to look for next.

Do I disassemble it and put it back together out of the case? If so, what do I hook up?

Thank you for any and all help offered.

[rjfvillarosa]

An out of case rebuild is usually related to a new machine that won't boot and is a test to see if the motherboard is shorting to the case, in this instance the machine was working before the storm and unless something fell down the back of the motherboard when you changed the PSU then I doubt if the motherboard is shorting in anyway.
The most likely scenario is that when the PSU blew it took the motherboard with it, do you know the make and model of the dead PSU?

[Pharaohwolf]

Originally Posted by seafrog3 My son brought his computer over for me to fix. He had, had a power surge during this last storm and the computer quit working (was plugged into a surge protector power strip). No light on motherboard when turned on. Figured it was the power supply. Installed a new one. Now the red board light comes on. The fans (case, chip, etc.) start up and the blue LED lights come on. This lasts about 4-5 seconds. Then everything goes dead. No red MB light, fan or anything. No time for the motherboard beeps or anything. I disconnected the case fans and CD/DVD drives in case they were pulling too much power (it would not stay on long enough to get warm, let alone HOT). Cleaned out dust bunnies the size of mice (vacumed and blew out dust). I re-set the boards, etc. Further info: Home assembled computer, ABIT NF7 MB, Athelon chip, Kingston memory, WD hard drives, etc. Please tell me what to look for next. Do I disassemble it and put it back together out of the case? If so, what do I hook up? Thank you for any and all help offered.

The best way to diagnose a problem that you suggest is to remove anything attached to the Motherboard except for a known good video card, processor, and memory. This is important to use known good parts rather than anything that was attached to it before it quit. You already stated that you were using a different power supply so you shouldn't need to get another one for this test. Attach the monitor to the video card. Be sure to plug the fan in for the processor. The case fans are not needed for this test. Also attach the keyboard. Now power the computer up. If you do not see anything come up on the monitor (memory counting, drives being recognized,splash screen, etc.) or cannot even get to the BIOS then you will first need a new Motherboard. If you are able to get it to boot to BIOS then you need a new processor and/or memory (I would change memory just to be safe considering the power surge) and then try the rest of the peripherals one at a time to test if they are working. If the motherboard does attempt to boot let it finish until hangs at /no drives found or /no operating system installed or something similar to these. The main thing is it will not try to go any further until you start adding things back in. Try going this far with it and then repost as to your prograss and I or someone else on this forum can help you with more. Good luck.

[seafrog3]

Thanks for the help.

rjfvillarosa - A fried MB is what I am afraid of. My son took the PSU with him when he picked up the new one. I do not know what it was.

Pharaohwolf - I do not have access to known good MBs, memory, etc. Looks like I will have to take a chance and replace the MB and other parts one by one until I get it right. I know this is not the cost/time effective way but I really have no real choices.

Looks like I know just enough to know that I do not know enough!

Thanks for the replys anyway.

[Pharaohwolf]

Originally Posted by seafrog3 Thanks for the help. rjfvillarosa - A fried MB is what I am afraid of. My son took the PSU with him when he picked up the new one. I do not know what it was. Pharaohwolf - I do not have access to known good MBs, memory, etc. Looks like I will have to take a chance and replace the MB and other parts one by one until I get it right. I know this is not the cost/time effective way but I really have no real choices. Looks like I know just enough to know that I do not know enough! Thanks for the replys anyway.

I just wanted to clarify. I wrote that you needed to use a known good processor,memory,and video card to test the motherboard's functionality. Only then can you determine what is causing your problems. One other thing you could do is take your processor, memory and video card to your local computer repair shop and have them tested. If they test good then your motherboard is the culprit. Or take the motherboard in and have it tested. Either way until you use a step by step process of elimination you will spend alot of money on parts you may not have needed. Again good luck and keep trying. That is how we learn.

[Pharaohwolf]

Also I wanted to add that considering the cost of motherboards as compared to the other parts of the computer it IS cost effective to eliminate it as the problem first. Then the other parts.

[glc]

You should use the out of case method to troubleshoot.

http://forum.pcmech.com/showthread.php?t=168456

[seafrog3]

I wish to thank those who offered advice to me. No one hit the nail on the head BUT I did find the answer.

First I would like to apologize for the delay in getting back to you. With the holidays, I put things off. Now back to the solution.

While laying in bed the other morning and thinking about the dismantling, reassembling, taking to the computer experts, etc. It hit me. The on/off switch was the problem.

A bit of history. When the computer would not start up, my son tried several things. One of which was to try shorting out the on/off switch. He broke one of the wires off. The switch was in a place that is almost impossible to replace without totally dismantling the computer so I did not replace it then. We had been touching the two wires together (and leaving them touching) to start the computer.

I know that all you "experienced" people know that the switch is NOT truly an on/off switch as we usually think of them. It ONLY "jumps" the motherboard pins. It does not stay on like a light switch. This is probably so obvious to you but not to us learning people. I know that I had not given you this crucial bit of information when asking for help. I did not know that it was crucial at that time.

I now know that everything was starting up but then while the two wires still touched, it turned the computer back off.

WHAT AN IDIOT!!!!!!!

The computer now works great. A new on/off switch and the new power supply was the cure.

I have learned much from this experience. It has made me more determined to learn more. Perhaps next time I will look for a horse in the horse herd, rather than a zebra. Always look for the simplest answer (Occam's Razor).

Sorry this is so long but could not explain in less words. I wish to thank each and everyone of you again.

Seafrog

[Cricket]

Thanks for coming back and letting us know what the problem was. Glad you figured it out.

Cricket