USB Doesn't Work During PXE Boot With Dell Dimension 5150 BIOS A07

[CLIFFORD ILKAY]

Hi,

I thought I'd share my recent adventures with a Dell Dimension 5150. It
all started a few weeks ago when the machine would not power up. More
correctly, the power LED would only flash amber a few times and nothing
further would happen. The power LED should be green when the machine is
running normally. According to various on-line accounts, this was a very
common problem with these machines. I checked the warranty status and
found it had 79 days remaining so I called Dell. They offered to send a
power supply and motherboard and would have sent a technician on-site
but I knew that would have only delayed the process so I agreed to
replace the parts myself.

The parts arrived in a couple of days and the first thing I replaced was
the power supply. This time, the amber light was consistent but still,
there were no other signs of life so I replaced the motherboard. The
machine booted fine with the new motherboard.

I have a Cobbler installation server that has local mirrors of the
Fedora 10 and Fedora 11 repositories and I wanted to do a kickstart
installation of 11 using PXE so I rebooted. I had the BIOS boot order
set to PXE, Optical device, and hard disk and the default boot option
for the menu presented by Cobbler was to boot from the local hard disk
if there is no selection made in 30 seconds. The other options are the
various installation profiles, Fedora 10 32 or 64 bit, desktop or
server, and the same for Fedora 11. I tried to select Fedora 11 64 bit
server but the cursor control keys had no effect. Caps and num lock had
no effect either. The only keyboard option on that machine is USB so
without any means of selecting the menu, the PXE boot timed out and the
ROM on the network card passed control over to the mbr of the hard disk
from which it booted successfully. I could have changed the default boot
option to be whatever I wanted in Cobbler but why should I have had to?
I had done countless test installations on the very same machine prior
to the PSU/motherboard failure so I knew it was feasible.

I called Dell and of course explaining the above to them was a big
challenge. Their solution was to send me another motherboard. When it
arrived in a couple of days, I replaced the second motherboard but
unfortunately, it misbehaved in exactly the same way. I had noticed the
date on the BIOS reported on POST was about 10 days prior to the date on
the web site but the Dell support people couldn't tell me if that was
significant or not so I decided to flash the BIOS by creating a bootable
USB key running FreeDOS and copied the .exe BIOS update from the Dell
site onto the key. I doubted it would make any difference especially
after I was prompted to confirm if I wanted to replace the A07 version
with the A07 and of course, it made no difference. Dell had no answer
and I had a machine that wasn't working like it was before this all started.

A few days later, I was at the school from which the machine above came
and picked up a couple more Dimension 5150s onto which the plan was to
do a Cobbler install of Fedora 11. I noticed that the first of the
machines reported an A05 version of the BIOS. Without even thinking
about it, I rebooted and upgraded the BIOS using the USB key to A07. On
reboot, it was misbehaving in exactly the same way as the other machine,
dead USB keyboard while the PXE boot ROM had control. I immediately
plugged in the other machine hoping that it was A05 and danced a jig
when I saw that it was. Sure enough, I had USB keyboard control on that
machine and could select any of the options from the boot menu presented
by Cobbler.

I had just confirmed that this was a BIOS bug with the latest BIOS
available for that machine so I called Dell and explained the situation
and asked if there was a way to revert to the previous version of the
BIOS. Some (many?) motherboards have a backup ROM so that if the BIOS
update fails, the machine isn't bricked. No such luck with Dell but
after consulting engineering, I was told to type "y:\something" at which
point I reminded him that I had no Y: drive and that I had booted from
the USB key as the C: drive. He didn't seem to understand what he was
talking about so I ignored the irrelevant part about the Y: drive and
ran the BIOS update with the "/forceit" option. After it asked if I
really, really wanted to downgrade and I confirmed that I did, it went
off on its merry way to overwrite and verify the BIOS. After a minute or
so, it prompted me to hit "any key" to reboot, which I did. It didn't
reboot. It powered down. Any attempts to power up have been
unsuccessful. I called Dell support again and they had me remove the
CMOS battery. That didn't help. For good measure, and clearly not
understanding that removing the CMOS battery did the same thing, the
tech had me remove the jumper next to the CMOS battery, though he,
incorrectly, didn't have me short the two other pins of the three in
that block. He had me remove the RAM to see if it would complain with
beep codes, which it did. He had me remove the add-on video card and
remove the CMOS battery again to force it to use the on-board video card
that I wasn't even aware existed. None of that helped so I now have a
bricked machine while Dell support talks to engineering to figure out
how to roll back to A05 without bricking the machines.

Of course figuring out how to roll back to A05 is an imperfect solution
since it means we'll have to put big warnings all over those machines
"DANGER! DON'T UPGRADE TO AO7!" The ROM is soldered to the BTX
motherboard so replacing it isn't an option. What a mess!
-- 
Regards,

Clifford Ilkay
Dinamis
1419-3266 Yonge St.
Toronto, ON
Canada  M4N 3P6

<http://dinamis.com>
+1 416-410-3326
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