PC won't boot

  • Thread starter Thread starter Charles Lavin
  • Start date Start date
C

Charles Lavin

Hi --

I have a Pentium III computer with an as-yet unidentified motherboard that
refuses to boot. The motherboard has an Award BIOS.

If I plug in a TechAID tester into a PCI slot and power up the PC, the
tester displays "FF" and that's as far as we get. The power supply indicator
lights light up in what seems to indicate a "pass" condition.

According to the Award BIOS code list, an "FF" is a "booting" message. The
TechAID manual says that getting stuck on an FF can indicate a problem with
the processor, PSU or BIOS.

If I plug in an ATX power supply tester into the ATX connector and switch on
the PSU, the tester beeps (which according to the manual indicates that the
PSU is OK), but the -5v LED does not light. (The other six LEDs do.)

If I replace the processor with another PIII, I still can't get past the FF.
I've also drained the CMOS, which also didn't help.

All other PSU connectors test OK. When I power up the PC, the HDD spins up
and the DVD-ROM initializes.

What can be the problem? Is the PSU bad? I don't have a functioning spare
PSU here; I'd have to buy one to run any tests.

(And what is the -5v lead used for? I can't find anything that mentions it
besides being on the connector.)

Thanks,
CL
 
I should add the following:

The computer won't boot. When you turn it on, you hear the PSU fan; you hear
the HDD spin up; you see the DVD-ROM LED flash while it initializes. When
you open the case, you also see the processor fan spin. But that's it. No
display. No beep from the speaker. Nothing happens.

To switch off the PC from the front power switch, you still have to keep the
switch depressed for 4 seconds before the PC switches off.

CL
 
On Sat, 05 Feb 2005 00:24:32 -0500, Charles Lavin wrote:

The -5V isn't used by anything important. RS232 serial ports use negative
voltages, although it's more likely that it's -12 but it might use -5.

Is the BIOS displaying anything on the screen? If you aren't getting
anything on the screen then it could be a bad display adapter also.
 
I just discovered that the -5v LED doesn't light on the tester because there
isn't a -5v lead on this power supply! The pin in the ATX connector is
empty.

I was going to check the video card as soon as I finished reassembling the
PC.

Thanks,
CL
 
Back
Top