can't charge or turn on T42, what is the problem?

[gychang]

My beloved T42 has developed a problem.

My battery can't be charged and with AC adapter plugged in. With the nearly empty battery in and with the AC adpter plugged in when I power up the T42, the lights come on briefly and dies in about one second.

AC adapter is working since I can measure 16V(DC) at the tip of the AC adapter. Thinking maybe it was a poor connection at the tip of the adapter and T42, wiggling the connection does not fix the problem. I would think if the T42 has "burnt" motherboard, it would not turn on at all.

Any experts suggest a further way to trouble shoot? thanks,

gychang

[Harryc]

What happens if you try to power up the T42 with the battery removed?

[frankiepankie]

I would check the systemboard fuses. Somewhere on this forum there is a T4x fuse scheme floating around, look at it for the fuse locations

[gychang]

What happens if you try to power up the T42 with the battery removed?

nothing happens, no brief light on, nothing!

gychang

[gychang]

I would check the systemboard fuses. Somewhere on this forum there is a T4x fuse scheme floating around, look at it for the fuse locations

search for fuse, no luck for me...

gychang

[ajkula66]

Try this old trick:

Remove the battery, unplug the adapter, pull out the hard and media drives.

Press the "power" button ten times in a row, holding it down for ten seconds each time, and thirty seconds the last time around.

Plug the adapter - but nothing else - back in and try to power on.

Good luck.

[gychang]

Try this old trick:

Remove the battery, unplug the adapter, pull out the hard and media drives.

Press the "power" button ten times in a row, holding it down for ten seconds each time, and thirty seconds the last time around.

Plug the adapter - but nothing else - back in and try to power on.

Good luck.

little bit of vodoo technique with a brief silent player did not help. thanks for a suggestion.

gychang

[ajkula66]

My best guess - not the one you'd like to hear I'm sure - is that your machine needs a new motherboard.

I'd try - just to be dead certain of it - to borrow a known working keyboard someplace and test the unit with it one more time.

I bought a "dead" R50p once...all that it needed was a new keyboard. Not kidding.

BTW, the "voodoo technique" is an official IBM procedure...

Good luck.

[poshgeordie]

Fuses - go to my sig and download the How To list. In there is listed the fuses doc. (or just click here!)

Dead Thinkpad - we also see this if the Southbridge needs reflowing / reballing.

[VFR_firefly]

Sounds like you have a bad component somewhere.

If you have known good parts you can try taking it apart and swapping things.

I'd start with the Mobo bare with only the CPU installed and a known good keyboard and a known good monitor. If it still doesn't post then I'd swap out the CPU.

Yes, I had this EXACT SAME symptom you are having with a bad CPU. I tried EVERYTHING -even sent the Mobo into Superior Reball to fix the mobo. They reported that they reballed the GPU and that the mobo tested out 100% fine. I put it all together and it STILL didn't work.

In the end it was a bad CPU the whole time. It had the same exact symptoms you are having. I"m not saying that it has to be the CPU -but it could be. It also could be a few other things that might cause the laptop to behave thusly. If you have extra parts laying around like a spare machine that you know works this is a good way to test the parts you have if a bit labor-intensive.

It could be that you have a bad Mobo but I've never run into a bad mobo that wouldn't at least charge a battery. Never had fuse issues either but I guess all things are possible.

edited to add: I reread your initial post. If the machine will run at all at certain times it's not the CPU...

My issue was that it would just never do anything -not even charge and the light would light up for a second and then go back out until it was unplugged and plugged back in -only to go out in one second.

[gychang]

you may be right, I may just donate to a local shop. thanks for the input. gychang

Sounds like you have a bad component somewhere.

If you have known good parts you can try taking it apart and swapping things.

I'd start with the Mobo bare with only the CPU installed and a known good keyboard and a known good monitor. If it still doesn't post then I'd swap out the CPU.

Yes, I had this EXACT SAME symptom you are having with a bad CPU. I tried EVERYTHING -even sent the Mobo into Superior Reball to fix the mobo. They reported that they reballed the GPU and that the mobo tested out 100% fine. I put it all together and it STILL didn't work.

In the end it was a bad CPU the whole time. It had the same exact symptoms you are having. I"m not saying that it has to be the CPU -but it could be. It also could be a few other things that might cause the laptop to behave thusly. If you have extra parts laying around like a spare machine that you know works this is a good way to test the parts you have if a bit labor-intensive.

It could be that you have a bad Mobo but I've never run into a bad mobo that wouldn't at least charge a battery. Never had fuse issues either but I guess all things are possible.

edited to add: I reread your initial post. If the machine will run at all at certain times it's not the CPU...

My issue was that it would just never do anything -not even charge and the light would light up for a second and then go back out until it was unplugged and plugged back in -only to go out in one second.

[VFR_firefly]

you may be right, I may just donate to a local shop. thanks for the input. gychang

Give taking it apart a try -it's not brain surgery. Download the manual here.