BIOS fails to start

[rebel9884]

I've done some intermediate pc maintenance in the Navy, but i think this one is a bit beyond me.

Was in middle of playing game when pc froze. After hard boot, pc wouldnt start. No POST beeps occured. I have power to everything. I have blinking lights from activity on front of box. All fans come on and spin at proper speeds. Hard drive spins up fine.

I figured that it was either my mobo or cpu. Both were replaced to no avail. I used the same mobo so that using a different chip set wouldnt be a probelm in the troubleshooting. I tried d/c my HD and same problem. I tried removing my RAM and still no BIOS start up.

Monitors do not receive any signal either of course.

I'm stuck in my troubleshooting and have read through some of the threads here only to find people in similar but not the same situations. Any advice is greatly appreciated.

[Belrog]

If you boot up a MB with nothing connected (No RAM - just CPU) you should hear the POST beeps (unless you have a old MB that needs a speaker).

No POST beeps leaves you with problems in either the MB,CPU or power supply.

Make sure the CPU is fitted properly. A missing CPU can cause the MB to not respond at all.

You should probably take the MB back to the supplier and have them test it - you might have damaged the MB with one of the things you plugged in - like the HD.

When rebuilding it next time make sure to connect one thing at a time - to see where the problems start.

On occasion I have seen people plugging the VGA cable into the wrong graphic cards (Did it myself a few times :) ). If you have a separate graphics card (Which you probably do) your on board card will deactivate in most cases. And then when your separate graphics card breaks the system might go back to the on board video.

[Suspishio]

Rwductio ad absurdum suggests the PSU that plugs into the mobo isn't delivering the voltage.

Whaddaya think?

[rebel9884]

On occasion I have seen people plugging the VGA cable into the wrong graphic cards (Did it myself a few times :) ). If you have a separate graphics card (Which you probably do) your on board card will deactivate in most cases. And then when your separate graphics card breaks the system might go back to the on board video.

I actually have dual vid card installed besides the onboard one, but it is a valid point cause both monitors are plugged into same card.

But before i think about that being a problem i have to take into account that i'm not getting the POST beeps. So your previous advice about installing piece by piece is what i will be trying today. Thanks for your help. I'll post back here whst the problem was for others that read and have same issue.

[rebel9884]

Rwductio ad absurdum suggests the PSU that plugs into the mobo isn't delivering the voltage.

Whaddaya think?

I have been using a 700v psu, so i dont think its lack of power, but is it possible to have too much? All take into consideration that i have made no component changes for at least 3-4 months before this happening.

Thanks for the reply.

[Suspishio]

I have been using a 700v psu, so i dont think its lack of power, but is it possible to have too much? All take into consideration that i have made no component changes for at least 3-4 months before this happening.

Thanks for the reply.

No, it can't deliver too much. There is a big power plug from the PSU to the mobo. Either the PSU can't deliver on every wire or the Power Good line doesn't hold (in which case there may be a mobo problem. But you replaced the mobo, so it points to the PSU IMHO.

I've been wrong before!

[rebel9884]

No, it can't deliver too much. There is a big power plug from the PSU to the mobo. Either the PSU can't deliver on every wire or the Power Good line doesn't hold (in which case there may be a mobo problem. But you replaced the mobo, so it points to the PSU IMHO.

I've been wrong before!

Yeah, i'm kinda getting the impression that the PSU might ahve issues with its mobo connector. It snapped min fine, but like you said about distributing power, it may have issues there. I have another PSU i will try tonite.

[rebel9884]

Well, a new power supply did not do the trick. I have installed a brand new mobo, a brand new processor and brand new power supply. I disconnected all other components. Only processor is installed. Upon start i am having issues sometimes even getting power to stay on. Sometimes i have to press power button again for power to stay on. Now i have configured all power connections according to the manuals. Is it possible that i might have anything else improperly connected? (ex. case led connectors [hdled,power sw,reset sw])

Now i know that this motherboard has an audible beep that occurs during POST processes.

[Suspishio]

Such a shame that money goes out chasing stuff because of our suggestions - and then it doesn't work! Problems of diagnosing at a distance.

Can you please state clearly now what the problem is? I think that you can't keep the rig powered, is that right? With everything new it's no doubt time to have the monitor conencted in case there's something to see. Or did you mean that the mobo has an audible beeop but it's not doing it for you?

No doubt you've got the CPU fan running - that's a must, I reckon.

And maybe a keyboard too to see if the lights blink.

This is really awful for you.

[caperjack]

Is it possible that i might have anything else improperly connected? (ex. case led connectors [hdled,power sw,reset sw])

it sure is possible ,you may have them all in wrong except the PSW one, butt it would still turn on and run the computer.
do you have the P4 square 4 pin plug ,plugged into the motherboard ,usually on the motherboard near the CPU

[jamoosee]

I had a similar problem. Turns out that when I bent the machine over the corner of a desk everything booted up for a while. Now to find the bad connection. I reseated all cables etc. I think I may have a bad connection on the main board.

[Belrog]

I've also seen short circuits on a MB do similar things - or even broken tracks. As soon as things start heating up and physically expanding a broken track might open up too much, and something somewhere will stop doing what it is supposed to be doing...

Make sure you have no risers/loose screws underneath the motherboard that can short anything.