T21 instant death

[fox999]

For a long time I used my T21 with power adaptor connected. Few days ago I used my laptop on battery I noticed it worked normally until the battery was at %60 then the power instantly dropped to %5. I connected the power adapter to charge the battery but it was killed without even a scream. I bought a new replacement battery and power adaptor, now the T21 works fine on battery but as soon as I connect the power adaptor T21 dies instantly, I mean it is like you turn off your TV. I have two good power adaptor and batteries both do the samething when I use them on my laptop, but it works fine on battery. Any ideas, is there any hope for this old friend, thanks

[vanaya]

Are the power adapters original IBM power supplies?? Batteries tend to die and my guess in your situation one of the cells in the battery pack is dead. Hence the jump from 60% to 5%. How many cycles and what health does battery maximiser show? If you don't have the battery maximiser software you can d/l load from lenovo.com.Here is a link for T21 driver matrix.

[fox999]

Thanks, yes both are IBM, with the same rating as the original. I tried them on my T42, both work fine. Outputs are 16V, rated at 4.5A. I charged one the batteries with my power supply and it worked fine for about over an hour.I think the battery I bought over the Ebay fried something in my motherboard,.It seams as soon as it senses the charger shuts itselfs off. I really don't know it is software or hardware problem, more likely hardware. I have a dead T21 motheboard, as soon as I get some direction here I will start the surgery

[SMA]

Having a battery installed is not mandatory. These machines are designed to be able to run without a battery being present.
Have you tried to start the machine with the battery removed? Does it start then?

[fox999]

SMA,

I removed the battery and conneted the charger, it started booting up but half way through loading up the windows hung up. I removed the charger installed my old battery it booted up fine. Removed the battery put the charger back up, nothing it does not even turn on. put the battery back on boots fine. I looks to me the charging management system on the mainboard is damaged. Does a short battery can be responsible for this ?

[SMA]

As I read it, there is no reason to believe that the new battery is defect, since the problems started before that battery came into play.
Also I think that the old battery is usable since the machine can run on it.
But there is something wrong with the ThinkPad, since it cannot run properly from the mains. And it will most likely be the motherboard.

I do not think that it is reasonable to put the blame on the new battery. Any completely drained battery would have caused the death of that t21.

Your options will be to give up on that machine, get a replacement motherboard or see if you can repair it yourselves.
If you want to try yourselves, then I would suggest that you start with a visual inspection.
You should be looking for something loose or something looking abnormal.

Here is an example of what you might be looking for. I just found that last night on a t20 board.
t20_loose_capacitor

[fox999]

Thanks, I will start to take it apart see what I can find. I tried to chage the new battery with my power supply, it at first took a little charge under one Amp, then stoped excepting charge, it is now totally open. BTW I have charged the old battery with my power supply suscessfully several time. I can definitley say the new battery is defactive. I have a T21 motherboard with messed up ROM. Everything works except gives an error message indicating the ROM read error. I was wondering is there anyway to reload the ROM. Thanks for your help, I will post what I find.

[fox999]

I removed the mainboard and examined it very carefully, there is no sign of trouble that I can see visualy, I found two fuses on board, both checked out ok. Well I guess this one is goner. Thanks

[vanaya]

Just another thought, will it pass POST "naked". Now that you have disassembled it, try connecting only the keyboard and lcd. Sometimes the ethernet cards/NIC give a lot of trouble but not like this. But its worth a try since it costs nothing to remove it.

[poshgeordie]

I'd go further and post 'naked' into Bios - press F1 just after pressing the on off button - does it go into the bios screen?

Also download and run PC Doctor for T2x from rkawakami, one of the forum moderators who hosts PC Doctor in an ISO image:
http://www.kawakami-ca.com/ibm_t2x/ibm_t22_pcdiag.iso

Oh, and welcome to the forums Fox999!

[SMA]

Since no visual sign of something wrong has been found on the motherboard, I would get into checking some mosfet's.

The saying of a shorted battery and the instant shutdown makes me think of some high current, which again makes me think of a shorted mosfet.

Basically mosfet's are 3 legged devices and when failing, they usually shorts.
Therefore they can be verified in a way, similar to checking fuses. Just that the result should be the opposite. A good fuse is supposed to be short (zero ohm) and a mosfet is NOT supposed to be shorted.
Also with mosfet's one will have to measure 3 times - on all 3 combinations of 2 legs.

Besides from being 3 legged (transistor like) devices, mosfet's also comes housed in 6 and 8 legged chips. But there will still be only 3 terminal points. Just that some are duplicated on more than one chip leg.
Most of the mosfet's in a T21 (that I know of) are 8 legged ones. They are easily identifiable, since all legs on one side will be connected together.
There are many mosfet's in a T21.

To point out the mosfet's that I believe are relevant here, I will be referring to the T21 board scans hosted by Ray.
The links to the scans can be found in this topic.

On the top side of the board, the mosfet's of interest are in coordinate A5 bottom, B5 top, E7 left.
On the bottom side of the board, G3-G4-H3-H4, G4-H4 left.


About the other board, the one with the ROM error, I would say that we cannot assist on that one since EEPROM's are related to passwords and discussing that is prohibited by forum rules. Sorry.