sw said:
My friend has a clone computer with an Intel D845WN Motherboard.
Recently, his system became unable to start. Power supply is working.
but there is no boot-up or bios info showing up on the monitor. The
monitor is tested and works.. His hard drive works as we put his into
my machine and it booted up. ( which allowed him to recover his
data.) He replaced his bios battery but to no avail.
Could this be a bios problem. If so is there a way of checking or
flashing the bios to restore it?
Any suggestions you have would be greatly appreciated.
Cards like the following, can be plugged into the PCI slot
nearest to the processor socket. The card has a two digit
display. It displays a hexadecimal code, from 0x00 to 0xFF.
These cards are available on Ebay, and ship from Hong Kong,
and that is where you get the cheapest of these.
http://www.startech.com/Share/Gallery/Large/PCIPOST.Clarge.jpg
When the display first powers up, the display will either
show 00 or it could show FF. Those are "uninitialized" values.
As the BIOS starts to run, the BIOS contains code to write
to the PCI display card. For example, it could write "01" to
the display, if subroutine 01 was about to run.
Thus, the code is not an "error" code, but more of a
"progress" code. The numbers will flicker rapidly, when
a BIOS is working properly.
If a BIOS gets "stuck", then the display will also freeze
with the last written value on it. Say the value showed
"56". You'd consult a table of codes for the motherboard,
to determine what "subroutine 56" does. (See page 121 of the
manual, which is linked at the bottom of this post.)
The main benefit of such a card, is as a go/no-go display.
If the motherboard is broken, the display might stay at
the initial 00 or FF value indefinitely. That would tell
you no BIOS was executing. But it doesn't tell you why
that is. For example, the BIOS chip itself could be
erased or broken. Or, the main processor chip could be
broken. Or the Northbridge, through which passes the data,
could be broken. There are lots of causes for a failure
to execute BIOS code, and that display device will not
help you do a detailed diagnosis. (The card is not a
good investment, unless it is really cheap.)
If the BIOS chip is held in a socket, and the chip is
removable, you can buy a new chip from badflash.com .
There are other companies, similar to badflash, that perform
the same service. You tell the company, what the BIOS chip
part number is ("PMC1234" or whatever), and you also tell
the company, where they can find a copy of the latest
BIOS file. You send them $25 to $30, and they send you
a chip in return. You snap the chip into the socket,
and then try to get the board to POST.
See section 2.9.2 on page 73, as Intel has more jumper options
than other motherboards. As far as I know, the "recovery" position
is a boot block loader, and maybe that can be used to reflash
the BIOS.
http://download.intel.com/support/motherboards/desktop/d845wn/A6513601.pdf
Section 3.7 on page 91, details what to expect. You offer
the BIOS file on a floppy diskette, when the jumper is
set for recovery. If the "boot block" is functional in
the BIOS chip, and is being read, then the BIOS will
attempt to read the floppy drive. The computer monitor
will remain black, because there is no video driver. You
have to judge the completion of a BIOS reflash, by the
noise (beeps) and lack of floppy activity. This should
not be attempted, if the computer has recently displayed
signs of instability (crashes a lot), because if it
crashes in the middle of a flash, there is no guarantee
you'd get a second opportunity to flash it.
If the procedure on page 91 fails, you can pay the $25
to $30, and get a new BIOS chip. As long as the chip can be
removed from the (brown colored) PLCC socket, you can put
another one in place. If the chip is soldered (as it is on
a small number of boards), then removal is much more difficult,
and can result in permanent damage to the motherboard.
The total expense, in swapping in replacement components,
using the PCI POST card, and so on, makes diagnostic work
an expensive proposition for a home builder. And it still
might turn out, that the motherboard is bad (or the power
supply). At least the power supply, you can check the
voltages with a multimeter, if you happen to own a
multimeter.
(Power supply spec - see page 30)
http://www.formfactors.org/developer/specs/atx/ATX12V_1_3dg.pdf
That motherboard has two power connectors. It has
"ATX12V", a 2x2 square connector with two yellow wires and
two black wires. That is what powers the processor. The
main power connector, the one with a lot more wires on it,
is used to power everything except the processor on the
motherboard. Make sure both connectors are seated.
Paul
