P4C800 Deluxe, No Post

  • Thread starter Thread starter Philburg2
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Philburg2

While messing with the bios, I entered some improper values. I set the FSB
to 400, instead of 200. Anyways, the easy fix is to clear the CMOS.
Unfortunately, I am having trouble booting, even after clearing the CMOS.
Nothing I do will work.

The system starts up normally, you can hear all the fans, HD, and the CD
roms kick in. But I get no signal on the monitor and the USB and PS/2
devices don't light up.

I don't want have to RMA the board for something simple, any ideas?
 
Philburg2 said:
While messing with the bios, I entered some improper values. I set the FSB
to 400, instead of 200. Anyways, the easy fix is to clear the CMOS.
Unfortunately, I am having trouble booting, even after clearing the CMOS.
Nothing I do will work.

The system starts up normally, you can hear all the fans, HD, and the CD
roms kick in. But I get no signal on the monitor and the USB and PS/2
devices don't light up.

I don't want have to RMA the board for something simple, any ideas?
Click to expand...

I hope when you cleared the CMOS, that the computer was switched off
on the back. Or, for good measure, the cord was pulled from the
wall. That is a good practice anyway, to make certain there is no
power in the computer while you are working on it, removing cards or
DIMMs etc. You don't want the green LED on the motherboard to be glowing
while clearing the CMOS, as a dual diode that powers the Southbridge
CMOS ram can get damaged if +5VSB is still running, while you are
clearing the CMOS. That is detailed in most Asus manuals.

If USB and PS/2 devices aren't lighting, then your +5V is dead.
(You know the +5VSB is working, because it is needed to start
the PSU running.) There are polyfuses in the path to those
devices, and those kinds of fuses automatically recover from
an overload after they cool off. They are a conductive substance
that open circuits at high temperature. So, that isn't the problem.
It could be a PSU problem, but hard to believe that just that one
supply output is dead or being shorted.

Do the hard drive and CDROM flash their lights at power up ?
They rely on +5V for that function.

If the motherboard thinks the BIOS is corrupted (checksum
failure), then inserting the CDROM that came with the motherboard,
can give the BIOS boot block something to use to reflash the
BIOS. Turn on the power, open the CDROM tray, and insert the
Asus CDROM. Somewhere at the root level of the CDROM, should be
a file like "P4C800.rom", and the motherboard can use that to
reflash the BIOS. Let the system sit for a while, or until you
hear a series of beeps, indicating flashing is complete. If
the power fails or you mess around before flashing is complete,
a complete failure of the BIOS to boot can be the result.

If you remembered to archive the original BIOS file to a floppy,
as recommended by the manual, you can use that floppy instead
of the CDROM, to restore the BIOS that shipped with the board,
rather than the older BIOS file stored as P4C800.rom on the
motherboard CDROM.

This is assuming, of course, that a BIOS corruption is the root
of your problems. If the motherboard won't touch the floppy
drive or the CDROM drive, then something else is wrong.
Reassembling the system on a piece of cardboard, and removing
unnecessary components, will allow you to add components one
at a time, until the board stops functioning.

HTH,
Paul
 
As said, I've already cleared it. I get no beep code or voice message, but
I'll try again.
 
Problem solved. This was the damnest thing and it didn't make a whole lot
of sense. Anyways, I started swapping out parts like the VGA and the Ram.
Well the video did nothing, but once I switched out the ram it worked and
posted fine. So bad ram right? No, I take that ram and stick in another pc
and that one boots fine too. So I'm sitting here going WTF. Turns out that
by default the bios can't post off of my kingston PC3200. Does that make
any sense to anyone? Once we reenter bios with the other ram, we can set it
up and then plug in the kingston again. Then my friend messed with some
settings and we had to do it again....

Thanks for those who gave advice.
 
"Philburg2" said:
Problem solved. This was the damnest thing and it didn't make a whole lot
of sense. Anyways, I started swapping out parts like the VGA and the Ram.
Well the video did nothing, but once I switched out the ram it worked and
posted fine. So bad ram right? No, I take that ram and stick in another pc
and that one boots fine too. So I'm sitting here going WTF. Turns out that
by default the bios can't post off of my kingston PC3200. Does that make
any sense to anyone? Once we reenter bios with the other ram, we can set it
up and then plug in the kingston again. Then my friend messed with some
settings and we had to do it again....

Thanks for those who gave advice.
Click to expand...

When a motherboard is set to get its RAM parameters "By SPD",
it reads the required settings from the tiny eight pin SPD EEPROM
on each DIMM. The motherboard trusts those settings, applies them,
and if they don't work out, bad things could happen...

If your motherboard has Voice POST, you should have heard some kind
of error message.

In some cases, Asus has actually added conditional code to the BIOS,
to ignore the SPD for certain brands and model numbers of DIMM. I've
seen this, by searching for DDR model numbers in the BIOS files
with a hex editor.

There have been some DIMMs, where the timing specs on the DIMMs
changed after introduction. For example, some Hynix memories have
a different CAS rating, depending on whether they are used on an
AMD versus a Pentium motherboard.

Makes me wonder though, how you got the motherboard to go in
the first place ? Something must have set up the timing to
non-default values, before that Kingston got put in there.

HTH,
Paul
 
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