HowToFixComputers.com

Exray · Guest

Early this month, I was planning to put a 2600+ CPU into a KT7AR mobo. It's
been an interesting experience.

The 2600+ cpu came from an HP machine that just_refused_to_post. It worked
for 3 years, the screen froze one day, the power button was pushed, and
poof...gone. Fans were working, the machine has enough parts to scavenge
for other machines....was time for a new xmas gift for wifey anyway.

So I took down my KT7AR machine (version 1.0 with next to last bios in
it...don't recall the number but it's been fine). I'd never experienced the
boot problems some people spoke of when upgrading to an athlon that is
supposedly "not supported", though the machine wasn't always the most
stable. There were times it would run for a day and freeze up, other times
it would run for weeks without any problem at all. It was VERY dusty in
there, I did a lot of cleaning, did a lot of huffing and puffing
(literally), did quite a bit of careful q-tipping. Put some fresh grease on
the heat sink, installed the 2600+, put just the agp card back in, and
.....nothing. I had apparently recreated the problem with my wife's machine.
AHA....bad CPU.......Nope.

Put the ol' trusty 1900+ back in there...and ...same problem.

I have been pulling power connectors from drives, running motherboard on
desk with parts scattered all over, assumed the problem must be a lazy power
supply and bought a 480W one and installed it, tried the old 700 meg Duron,
tried an ISA video card instead of the AGP....same results.

Now I can get the computer to post. All I have to do is clear the CMOS.
Then when I power up again and nothing happens, all I need to do is hit the
reset button, cross my fingers, ignore the message that I have a CMOS
checksum error and hit F1. I have the 1900+ back in there. Yes, it's
defaulting to 600 mhz, so what I've done is to trade a very dusty reliable
machine for a clean and slow and finicky machine.

I did get it to post and run with the 2600+ once or twice. At 600 mhz, the
1900+ is running at 35C. The 2600+ came up as an "unknown 2000 Mhz" and ran
at 50C. Seemed too hot for my taste, so I am back to the 1900+ and I know I
don't have a dead CPU.

What I can't do is go into the bios, change the settings, save the settings,
and expect the machine to post. I can change the time in windows, and the
CMOS remembers that change.

All suggestions are welcome.

Thanks

Exray · Guest

Since the computer is capable of a warm start with a cleared CMOS, I
speculated that perhaps I should do what many people are always
suggesting....change the battery. The KT7A has a much less straightforward
battery clip than the non - A - did, but I managed to get the old battery
out, and by gosh it was reading something like 2.65 volts. AHA....the
solution is at hand.....new battery, 3.2 V, clear the CMOS, and we're good
to go...right? Nope. No go. Same result.

The other thing I notice is that the hard drive light is on full time when
the machine is in its won't_do_even_a_flash_screen, won't post "mode". I
don't know if that's significant. Of course there's the dog that won't
bark. The only beeps I get are the single one when the system finally
decides to let me boot.

I feel that I've exhausted most of the remedies.

I've read that on some newer motherboards there are LEDs that are slightly
diagnostic built in. Does anybody know of an add-on, something that might
plug into a PCI slot and gather and display information on where the cold
boot process is hung up? I suppose one could hang a logic analyzer on the
address bus of the BIOS chip and just watch the program execute (or not),
but that seems way overboard.

Thanks for reading this far. It's a part time science project, I guess.