No BIOS beeps. No Picture. Has my CPU blown?

  John Ba 17:33 22 Nov 05

My computer was recently diagnosed with a faulty motherboard and I subsequently discovered that my power supply had also blown - in fact the two were probably related.

I consequently bought a new motherboard, ensuring that it was compatible with the CPU, memory, hard disk, graphics card and the new, 500W power supply.

I carefully connected up the new motherboard, making sure that the hard disk was connected to the IDE 1 connector and that the motherboard was set for the right CPU clock speed.

On switching on, though, the two optical drives span (I've disconnected the floppy drive) and the hard disk also did so. The system case, CPU and graphics card fans all worked. However, there were no BIOS beeps and absolutely nothing appeared on the screen.

I've tested the hard drive on another computer and it works, though I didn't try to boot from it (and I've reset the hard disk jumper back to its original setting). The screen is also in working order.

I took out the motherboard's battery for half an hour to clear the CMOS as well as checking that its voltage was ok.

I've also taken out the AGP graphics card and two PCI cards to see if the BIOS beeps would reappear but without success.

Is the most likely cause of the problem that the CPU has also blown? Could it be anything else, perhaps to do with the graphics card? And can you suggest any further tests to help diagnose the problem?

With thanks in advance for any help or advice that you may provide.

  Skyver 18:01 22 Nov 05

It sounds like your CPU is toast aswell, no beeps at all even with graphics card removed is a good indication.

  Skyver 18:02 22 Nov 05

One thing to try is only fitting one stick of memory at a time (assuming you got more than one), just on the offchance.

  John Ba 21:12 22 Nov 05

Thanks for your suggestion. I'll try swapping the memory sticks, but like you I rather fear that the CPU's been fried.

  josie mayhem 22:12 22 Nov 05

Have you checked that you have the case speaker connected? As on my set up, the post beep comes from the case speaker and not my surround speakers.

  John Ba 09:48 23 Nov 05

Thanks for this further suggestion. However, the computer doesn't have a case speaker, but I'm running some external speakers from the Line Out connection of the motherboard on the back panel. Do you think this matters? And do you think it would make a difference if I used the F_Audio (Front Audio Panel Connector) directly off the motherboard?

With many thanks for any further thoughts on this.

  Gongoozler 10:01 23 Nov 05

Hi John Ba. The external speakers are unlikely to give POST beeps, and so are of little help in diagnosing your problem. See if you can get a speaker from an old computer. A case I recently boaught had a little piezoelectric speaker like these click here.

When you have a case speaker, remove everything from the motherboard except the processor with it's fan, power supply, case speaker and power switch. You should then get an error beep from the case speaker. complaining about lack of memory and graphics. If that doesn't work, remove the CMOS battery for about 10 minutes, refit it and try again. If you do get the error beep, start rebuilding the computer a component at a time - starting with the memory and see how it goes.

  John Ba 10:37 23 Nov 05

Hi Gongoozler. This sounds like a very good idea. There appear to be two places where I could attach a tiny peizoelectric speaker to the motherboard:

Option 1) To use the F_Audio Panel (Front Audio Panel Connector) which has 10 pins and includes front, rear, left and right audio as well as microphone pins.

Option 2) To use part of the F_Panel (Front Panel Jumper). There appear to be 4 pins in a row (though the 2 centre ones are not used) to run a speaker from. The rest of the 20 pin connector runs the front panel LEDs, the on/off switch and the hardware reset switch.

Which of these options do you think would be preferable (I suspect Option 2)?

And if I still get no BIOS beeps, when all the other components have been removed, I imagine that means the CPU is fried?

With thanks once again for any help that you may provide.

  Gongoozler 10:46 23 Nov 05

Hi John Ba. The connectors you must use are those on the 20 pin front panel connector.

When all the components have been removed and the CMOS thoroughly reset by removing the battery - and ensuring that the link isn't in the reset position, if you still get no POST beeps then the only parts that can be causing the problem are the few that are remaining. You can try touchng the power switch contacts together just in case that is the problem, you can also try with just one stick of memory, although usually with no memory at all you will get the error beeps. You can also try unscrewing the motherboard from the case and resting it on a sheet of card to eliminate the possibility of a short to chassis.

  John Ba 10:54 23 Nov 05

Hi Gongoozler. I think I now understand what I have to do and will go and purchase a piezoelectric speaker.

With very many thanks for your help.

  Gongoozler 11:10 23 Nov 05

Hi John Ba. I see that you have ticked this thread as resolved, but please let us know how you get on, and before you go looking for a case speaker and dismantling you computer, check that the CMOS link isn't in the reset position, and try removing the battery for 10 minutes or so, that has worked for me in the past.

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