standby - goes into standby for no apparent reason

[wsm]

I originally posted under http://forum.thinkpads.com/viewtopic.php?t=46274 but I'm not so sure now this is a traditional heat problem.

This T40 for no apparent reason drops into standby (standby light is on) or totally drops power, either while I am in BIOS or with the OS up. I am testing without a battery.

With another unit I have removed or swapped power supply, CMOS battery, fan+heat sink, keyboard, disk, memory, bluetooth, network. I am at the point on where the only removable item not changed on the machine is the CPU.

BIOS is at 3.21 2006-06-02 and controler v1.02
the newest available are 3.23 2007/07/03 and v3.04 respectively.

Them machine does stay up longer coming from dead cold.
Thereafter it fails without touching it anywhere from 5 sec to one minute. However, while in BIOS I can cause it to die cooincident with pressing a key upon entering config or changing a value in config. Another symptom is while in BIOS config sometimes the movement from field to field is very slow.

ideas?

[jdhurst]

<snip>
This T40 for no apparent reason drops into standby (standby light is on) or totally drops power, either while I am in BIOS or with the OS up. I am testing without a battery.
<snip>
ideas?

If you are working without a battery and the machine drops power, then I would consider the power connection inside. That is what I have seen.

To the best of my knowledge a machine *cannot* go into standby if there is no battery *and* the AC power has dropped.

There could be a motherboard error but I cannot help you there.
... JDH

[richk]

It is hard not being able to see the machine, but my guess is that the power jack is sick.

[wsm]

I wish the solution was so easy

* dies same way with battery (so probably not power jack)


> To the best of my knowledge a machine *cannot* go into standby if there is no battery *and* the AC power has dropped.

excellent observation - would be nice if true

[wsm]

at the suggestion of an electronics friend, put the thinkpad in refrigerator for an hour - made no significant difference in failures.

[The Spirit of X21]

> To the best of my knowledge a machine *cannot* go into standby if there is no battery *and* the AC power has dropped.

excellent observation - would be nice if true

Wait, doesn't this have to be true? I mean, if there isn't a battery and AC drops (i.e., no power at all), the machine physically cannot go into standby, right? It just turns off.

[wsm]

[quote="The Spirit of X21"][quote="wsm"]
> To the best of my knowledge a machine *cannot* go into standby if there is no battery *and* the AC power has dropped.

excellent observation - would be nice if true[/quote]

Wait, doesn't this have to be true? I mean, if there isn't a battery and AC drops (i.e., no power at all), the machine physically cannot go into standby, right? It just turns off.[/quote]

you would think. but no, really!, it occasionally sleeps and can be revived by hitting power. Note - i did not physically disconnect power. Whatever happened, the machine did on it's own.

So with these strange and sometimes conflicting symptoms I have not been able to definitively say whether it's power, heat, or something else.

i have done everything** short of removing the MB and doing the heat/resolder thing i've seen mentioned. I'll be really [censored] if I buy a $200+ replacement MB and it doesn't fix it.

** removed/reseated/exchanged every single removable part,/card/chip/etc including the CPU