T42p not booting. Power indicator off. No beep, no LCD. What can we do?
After spilllage of tea-no-sugar, the laptop shut itself down.

Trying to rectify this, we disassembled the beast, cleaned the motherboard (did not remove the CPU, as it was too hard to get it out) and keyboard using isopropyl alcohol and re-assembled the machine.

But, it would still not work! Here is what we have tried:
1. Connected power and battery. Beast showed amber battery LED. I pressed the power button. Now, the battery LED went off again.
2. Removed
- RAM (standard and option)
- BT/modem daughterboard
- Wifi board
- HDD
- DVD drive
- speaker assembly
connected keyboard and AC power. Pressing power button. Still no lights, no fan, just deadly silence.

What now, brown cow?

Sounds like the motherboard is probably dead. But, how long did you let it dry before trying to power up again? The general rule of thumb is about 48 hours drying time, before it's safe to try applying power again.

I am sorry. The daughter and I were very impatient and re-assembled and fired up straight away.
So, under what conditions shall we dry this?
- disassembled
- in rice
- in the airing cupboard

Shall I pop out the CPU? If so, how (I have tried unlocking the screw. But, the CPU seemed very firmly seated)

Cheers

Oooh! Hope the damage isn't already done...

Air drying disassembled for 48 hours should be fine. In rice or the airing cupboard might speed things up a bit, just don't get in too much of a hurry either way. Probably not necessary to remove the CPU, but once the locking screw is open, it should just fall out of the socket. Might be something else wrong there too.

Got it. The beast is now taken apart again and resting in the airing cupboard.
CPU came out fine, after turning the screw all the way.
Now, when trying to start up again, how much will I need to re-assemble? Which parts are essential to check the mother board?
I want to have the least effort, while keeping number of parts obscuring the picture at minimum.

Thanks a lot for your prompt replies.

I suppose nothing more than the CPU, fan and speakers, No RAM or anything else, and apply power and listen for the 1-3-3-1 beeps indicating no RAM. If you hear the beeps, you can start adding stuff back...but if there are no beeps the motherboard is most likely done for.

Sorry to hear about the accident.

To be honest it could be anything but there are a lot of fuses on the board and one of those could have blown.

Download the How to Docs link in my sig, and within that list download the fuses doc. If you have a test meter a simple continuity check across each fuse will confirm their state.

Otherwise I do repair these boards and can do this for you; also I may have a refurb'd board but will need to check when I'm back at work on Wednesday.

PM me if interested in either option (I'm based in north east england).

What boards can I use here?
This T42p is model 2374-HTG. The original board, 93P4159, might be hard to get.
The CPU reads 7501A140, SL7EN, RH80536, 1800/2M. Does this limit the choice?
Gigabit Ethernet or security chip I would not require (it is all private use).

Thanks
Daniel

Following Use different FRU board than original?, I am now attempting to use a different board. Let's hope for the best.

Replacement Motherboard P/N 39T5454 fixed the issue.

Good job