Trying to fix a bricked X20

[rolfen]

Hi,

I'm trying to fix an IBM thinkpad x20 (2662-12G). When I plug it in the power, the battery icon, the sleep icon (that moon) and the Thinklight (it's a fancy name for a LED that illuminates the keyboard) go on. That's all, no sound, beep, display, click... nothing. And no reaction whatsoever to pressing the power button, Fn+PgUp or random keys on the keyboard.

I've also tested the battery and it *seems* (according to my limited knowledge) to be dead.

The power supply supplies 16V (the correct voltage) when unplugged. On the first run, we plugged in the wrong power supply - the one we used was for a printer: 30V. Maybe that damaged the laptop, or could be anything else that happened during all the time it was stored and not used (years I think) - yet it is rust-free and looks brand new. I also read somewhere that a discharged CMOS battery can cause weird symptoms.

I took off the keyboard and some other component and located so far two 5A fuses on the mainboard and tested them, they seem to be OK. Havent found the CMOS battery, and I read there are lots of other fuses.

I also took it to a repair shop, and the repairman, after a quick examination, said that there is a short circuit on the mainboard, because the Thinklight is on, and that shouldn't happen when the computer is not running - and the mainboard needs to be replaced.

So I post this here, wondering if anyone here has any suggestions as to what to do? My next step will probably be totally removing the system board, and testing all the fuses that I can find. I wish I could test MOSFETs, but I dont have the proper gear nor the proper know-how for that.

In parallel, we're looking for a replacement mainboard.

[topmahof]

take the ram chips out, take the hard drive out, turn it on and see if it gives you a memory error. if nothing happens then i'd say the board was bad. i've seen machines not turn on because of dead batteries also. if you do get the memory error then plug one chip at a time back in and see if you get the error or can get into the bios. if you have an external monitor that you know works you could plug it in and see if anything comes up on that screen.

[rkawakami]

Welcome to thinkpads.com!

From the sound of it, it appears that the motherboard is dead. My guess would be that it happened during the application of the 30V. If the Thinklight goes on as soon as the AC adapter is connected and without pressing the power button, then that is certainly not normal. By all means, try the advice that topmahof suggested (pull out all hardware and see if you get the 1-3-3-1 beep sequence when powering up).

[rolfen]

Thanks for the nice welcome and for the answers
I took away everything and am left with the bare board. I could not extract any kind of beep from it (strangely, there were no RAM in the slot - i think there is some onboard memory). But then, could the keyboard component or the power button be faulty? I haven't located any additional fuses on the board. If there are any, they aren't made obvious through their looks.
I noticed a faint click when I plug in the power supply, and if I put my ear on the board, I hear like the sound of a mosquito coming from somewhere close to the power connection.
I'll try to find out from what component it comes from. Otherwise I'm wondering if the battery light + the sleep light being on have any meaning.
I'm starting to think that the board might be hopelessly messed up, but haven't given up yet.

[topmahof]

well, i agree with rkawakami that it's not normal for the thinklight to go on automatically. also, 30 volts going to it is not a good thing. what color is the battery light. amber or green.

only one other thing to try that i can see. if the battery light is green leave the battery in and hold down the power button and then plug in the power and see what happens. if nothing then take out the battery and do it again. if again nothing, then see if you can see the cmos battery. it should be about the size of a U.S. nickel yellow in color and unplug it. hold the power button down for about 15 seconds and then plug in power and see what happens. yeh, i know, that's more than one thing, sorry. who knows, being that the ram is missing maybe the cmos battery is missing also. the cmos battery will just give a date and time error at startup it's not essential for startup. it's a real long shot but the power button could be bad but i'm more inclined to believe that the board is messed up.

[billp117]

30v will fry the board...sorry. I would start over and find another X series laptop.

[rkawakami]

I could not extract any kind of beep from it (strangely, there were no RAM in the slot - i think there is some onboard memory).

Ah yes, sorry I forgot that we are talking about an X2. These systems have 64MB or 128MB of memory integrated onto the motherboard. If you do get the bad memory beep code, then that would mean the motherboard is mostly good and that the on-board memory has been damaged.

But then, could the keyboard component or the power button be faulty?

It's possible but that does not explain why the Thinklight and the sleep LED are on when they should not be.

I haven't located any additional fuses on the board. If there are any, they aren't made obvious through their looks.

The motherboard uses surface mounted fuses which look like these:

http://www.kawakami-ca.com/ibm_t2x/main_fuses.jpg (two types outlined in blue)

[misfit]

The motherboard uses surface mounted fuses which look like these:

http://www.kawakami-ca.com/ibm_t2x/main_fuses.jpg (two types outlined in blue)

I hope that you don't mind Ray, I've saved that pic to my 'Repairs and Mods' folder in my ThinkPads folder.

You never now when you're going to need info like that.