[Thinkpad] A 770 (9548) in coma ?

Today I got my dirty hands on a first generation 770, model 9548.
(P233MMX, 32+128MB, 24xCD)
I got it for roughly $65 and bought it as being dead on delivery and arrival.

Of course I want it to come alive again. That's why I bought it. :´-) It's a ThinkPad 770.

It's kinda strange...really.
It's not that dead. Something is definately wrong, but I can't figure out what.

It's medical history, provided from the seller, tells this story:

One day it just won't boot.
He tries another HD...still no luck.
He puts it away for 14 days.
It now boots normally.....!
Windows is up 'n' running....
Suddenly it freezes.....light and image is still on the LCD.
Tries a reboot, but it freezes during Windows startup. Image on LCD is okay.
Tries a reboot one more time...freezes after only 20 seconds. LCD okay.
One more try.....but it won't even boot.
A couple of days later, he's trying again...but it's dead.
No mercy.

Now I have my hands on it.

I took out the Lithium 3V batterycell....only showing 0.03 Volts.
Replaced it with a fresh one.

At power-up....:
The power LED on top is working okay.
CPU-fan starts at high-speed....slowing down for a couple of seconds...then high-speed again permanently.
The floppy gets some juice...I can hear it getting some power, but the machine don't get a taste of it like in a normal POST.
I can't hear the HD running.
There's absolutely no POST going on.
No beeps.
The LCD is black. No life.

But...here's the strange part:
The indicatorpanel works !
It can charge a battery. I can see the gauge showing and counting the percentage.
It shows the NumLk, CapsLock and ScrLk indicators in the normal way at power-up...All 3 at the same time during a second or two.

On my beloved ;-) 770Z...I opened the HMM.
I disassembled the 770 totally. Ruling out bad connections. Reseating everything.
Got it back together again...still no life. With all peripherals off or on. No life.
I noticed a Standby-battery, NiMH. I took it out...it does have current, 3.9 Volts.
But a NiMH-cell can show a lot of current, but then having no capacity.

It's an old machine :-)
What is causing this coma ?
Is it the Standby battery, that's old and worn out ?
Is it the CPU-card ?
Systemboard ?

If it's a dead CPU....then it should be dead....dead as a stone the first time it wouldn't boot.
Same, I think.....goes with the systemboard.
Does a dying systemboard acts out this way ?
"No, sucker, I won't boot now. Wait 14 days"

The symptoms provided by the seller....I think, indicates something with a battery.
Leaving it for 14 days could bring some juice back to the surface.
Powering it up...see it running.
Then...in shorter intervals....it dies on him.

If it's the backup-battery....then it would boot and show some numeric error codes.
What if it is the Standby battery that's dead ?
There's no reference to this in HMM.

Am I on the right track ?

My very best regards.
Brian

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Received on Wed Sep 24 18:51:19 2003