T42 power problems

[missouri100]

Lots of good information on this forum but I can't find exactly what I need.

Troubleshooting so far:

** When I plug the AC adapter in I don't get the green charge light and it doesn't charge.
** I have left the AC adapter plugged in overnight and it didn't charge.
** The computer will not come on. The battery is dead.
** I measured the voltage coming from the charger and got 16.7 volts.
** I took the computer apart so I could get to the adapter socket. I unplugged the small white connector coming out of the back of the AC adapter socket. I plugged in the AC adapter and measured the voltage in the small white connector. It was good.
** I plugged the white connector back in and measured the voltage on the solder pads that hold the white connector socket. It was good.
** I put the computer all back together and tried it (had to try) and it still didn't work.

I found the following steps in another thread.

** I pulled the hard drive, CD drive, and battery and unplugged the AC adapter.
** I held the start button on 10 times - 9 times for 10 seconds and 1 time 30 seconds
** plugged the AC adapter back in and tried to turn it on. Dead as a hammer.

I am a big thinkpad fan and would like to fix this. Does anyone have suggestions as to what component could be bad or something else I can do for trouble shooting?

If the power supply is bad, would that keep the green charge light from coming on?

This computer was running with no issues until recently.

thanks

[Neil]

Just guessing here, but looks to me like either one or more system board fuses in the power circuit have blown, or the system board is just dead. I would begin by testing the fuses with a multimeter for continuity.

Oh!...and welcome to thinkpads.com. I didn't notice this is your first post.

[missouri100]

It appears I need to replace the system board. I have been researching motherboards and there seems to be several different versions. Can I get some guidance before I order a new one? Is there a version that is better? I have read several threads about replacing the the system board but just haven't found the information about which one. I would guess the different part numbers have different features but haven't been able to find the differences.

thanks

[Neil]

Any board from the T4x/R5x series is a drop in fit. They do have different features, but any will work. If you want to re-use the RAM and CPU from the T42, I would recommend a T42/R51 board, but they are just as likely to fail as the first one. A board from a T43/R52 would also be a physical fit, but needs different RAM and CPU. However, the T43/R52 boards, being newer and made with different techniques, are more durable.

Unless there is something really speacial about your T42, the best, and easiest fix would be to replace the whole thing with a newer model.

[RealBlackStuff]

Look at my list of T4x/R5x motherboards: http://theboardroom.info/ibm_list.htm

[missouri100]

Replaced the mother board - - works like a champ.

I have been buying and using thinkpads for years for programming factory automation. I can't tell you how happy I am to have found this forum.