T42p problem with Power

[ryer]

The beast (T42p UXGA 2373-HSG) starts OK from battery and then runs fine when plugged in... but it refuses to start when plugged in, and just the fan comes on and the battery and Z (in circle) light stays green but the screen remains blank.

I always have to unplug it to restart (which it does perfectly) and then plug it back in again.

Other than that it seems fine.

Any help appreciated.


PS.
The Disk was migrated from an Intel XGA R51 and drivers updated manually (as ThinkVantage System update couldn't be reset, even by deleting both it and its registry subkeys and re-installing!).

[ichhabegedroppen]

Hi There,

Have you tried removing the battery and trying to start if from just the AC Adapter?

Are both your AC Adapter and Battery Genuine IBM/Lenovo Parts?

[ryer]

Hi ichhabegedroppen

thanks for the reply, yes original charger and battery, both originally from an IBM T4X/R5X series and working well.

I replaced the battery with another but still the same issue, and no, it will not boot without the battery in place (only from the battery only with charger disconnected).

Another small issue is that the Screen bezel display panel (the green icons) sometimes flicker on and off, especially the battery one, although nothing else seems affected!

Edited to say: Actually also, machine will never come out of suspend even when on battery, and the power socket seems a little loose (but not excessively so).

So:
1. Machine powers up 90%+ of the time on battery only (it failed once for some reason).
2. Machine never powers up with power cord connected (I mean it powers up. lights, fan, but no LCD display, blank) .
3. Once powered up on battery power cord can be connected and system charges/works as normal.
4. Screen bezel lights sometimes flicker (but this is infrequent and only during heavy disk use, so perhaps the disk activity light affects the rest).
5. Machine will never come out of suspend, either on battery or power cord.
6. Power socket seems slightly loose, but not excessively so.

Other than that it works very well.

Many thanks again
Ryer

EDIT: Seems somebody else had the same problem with the T41!
http://forum.thinkpads.com/viewtopic.ph ... er+problem

[ryer]

Also puzzling... it fails to come out of hibernation... hangs right at the last moment after loading the image in.... disk occasionally flashes but no Windows screen comes up.....

Could this part be related to using a disk from an R51 that had all the Power Management stuff installed?

However the failure to start up on power connected of course can't be related to that!!!

Thanks! Advice appreciated.

[edik]

well the machine finally died.

but then after leaving it a month or so and plugging it in again it starts again - with exactly the same symptoms!

it definitely isn't GPU related. So, I wondering what can it be???

I am sure it may not even turn on again after poweroff (I am typing this on the problem machine and it works perfectly)...

any help GREATLY appreciated!

PS. Same behaviour even in dock!

[RealBlackStuff]

That machine (like all T4x) also has a Southbridge (big intel chip under the wifi card), which is most likely the culprit.
Try putting pressure on different parts of it, see if it then starts.
If yes, contact poshgeordie on the forum. He can reball it professionally (in Newcastle).

[ilakast]

That machine (like all T4x) also has a Southbridge (big intel chip under the wifi card), which is most likely the culprit.

Since, I inherited this machine from edik, let me update this topic. Indeed this is the http://www.thinkwiki.org/wiki/Intel_82801DBM chip. But luckily it seems the problem was not very serious.

Opening the laptop up and taking everything out seems to do the trick


I will now clean it up and start plugging in the wifi module etc. to see what caused the problem. I am very happy I brought it back to life

edit: Spoke too soon. Apparently it booted by chance; it most probably suffers from the MOSFET issue mentioned here http://forum.thinkpads.com/viewtopic.php?f=2&t=96848

Will update later on...