X31 charging woes - battery/AC power problems

[Ratskrad]

Hi All,
I have an old X31 that I am trying to nurse back to health. The battery and AC is screwed up! Have any of you guys had any similar experience?

Here is what I know so far:

1/ Battery, while far from new, is working fine (checked with a battery analyzer)

2/ Battery talks to system - ACPI reports correct vendor, Wh dischargre rate etc.

3/ AC adaptor powers system, but does not charge battery

4/ When battery alone is connected, the system power light turns on (even with system turned off) - ACPI reports AC adaptor is connected and system is charging.

The upshot of all this is that the system cannot charge the battery, and the battery appears to be an AC adaptor, meaning that leaving the system in the OFF mode with no AC adaptor connected will result in a fully discharged battery after 12 hours or so.

My first idea was that the steering FETs or fuses had gone bad - but all of them seem to be ok. I then suspected the battery charger chip ADP3806 (U39) - but this was replaced and the symptoms are still there.

I then changed the MAX1845 (U49) still no joy. Looking around I found the SuperI/O is PC87392VJG (U63) - but this doesn't seem to interface to the batteries.

My current train of thought is that there is some issue with the notebook power asic - Toshiba TB62501F (U55) - does this make sense, I can find the part on the web, but no detailed information about this part. From the Toshiba forums it seems like Toshiba have recently become very secretive about their chipsets I don't suppose anyone has a datasheet?

Thanks for any help you can offer.

Mark

[snv]

Hi Mark,

Welcome to the forum! Could you please clarify some points?

2/ Battery talks to system - ACPI reports correct vendor, Wh dischargre rate etc.

Is it an original IBM part? Do you know if the battery was re-celled and/or the chip in the battery replaced?

4/ When battery alone is connected, the system power light turns on (even with system turned off) - ACPI reports AC adaptor is connected and system is charging.

Do you mean that the system, essentially, cannot be shut off and there is always some power drain?
Is it the same when you remove the battery and plug in the AC adaptor?
Does the laptop function OK otherwise (have you tried to run PC Doctor)?

[Ratskrad]

Hi,

Thanks for the welcome and for so speedy a reply. Here are the answers to your questions:

2/ Battery is an original IBM part - I tried a new battery from a 3rd party vendor and the same thing happens. To my knowledge it hasn't been re-chipped - there are no tell tale scuffs or marks around the part line.

4/ Right - even tho the system is 'off', the orange 'batt' light stays on (normally indicates AC in, batt charging) - this light turns on when the AC adaptor only is connected, when AC adaptor and battery is connected, and also when just the battery is connected.

The laptop works perfectly otherwise using BurnInPro (Passmark software) - it would be a pity to scrap the unit. X31's are like Hondas - they just keep chugging along.

Mark

[snv]

Right - even tho the system is 'off', the orange 'batt' light stays on (normally indicates AC in, batt charging) - this light turns on when the AC adaptor only is connected, when AC adaptor and battery is connected, and also when just the battery is connected.

Just to confirm: Whatever you do, with the battery only, AC only, and with both, the laptop has the battery light on (green or orange), even if the laptop is turned off. Right?
Does the laptop powers on right after you connect it to AC, or you still have to press the power button?
What happens, if you press and hold the power button for > 5-10 sec?

The laptop works perfectly otherwise using BurnInPro (Passmark software) -

If you have the IBM service partition intact on the hard drive, you could try to run PC Doctor (if the partition is missing, I think, the program is downloadable either from IBM or Lenovo website). At least, this program was specifically designed to test ThinkPad's hardware.

it would be a pity to scrap the unit. X31's are like Hondas - they just keep chugging along.

I totally agree. They are not undestructible but sufficiently robust. I use an X31 as my main computer: it follows me everywhere.

[Ratskrad]

Ok - Finally got back to the real system to test it, rather than from memory. I found that AC adaptor does not light the BATT light.

1. Start with no battery, no AC adaptor, and system off
2a. Connect AC adaptor only, BATT light flashes then goes off and stays off
2b. Connect Battery only, BATT light goes green after about 5 seconds, then goes orange until battery is dead

In both 2a and 2b the system remains off until the power button is pressed then the system turns on normally.

If the system is ON and the power button is held for 5 to 10 seconds, it does a 'hard off'. If the system is off and the power button is held for 5 to 10 seconds, the system turns on, then does a hard off and tries to turn on again etc.

Ah - PC doctor in the service partition - yes it is still there (v2). The standard test completes with no errors.

Mark

[rkawakami]

I don't suppose anyone has a datasheet?

I looked around at all the usual sites that I know of (and a couple of new ones) and also came up empty on a TB62501F datasheet. Toshiba.com has a listing in the "Other Power Supply ICs" section but no .PDF for it.

The PC Doctor for DOS diagnostic may not be much help. About the only tests that specifically check the power circuits are AC Adapter and Battery. I believe those will be under the "Other Devices" menu. If either test fails, I have no idea what you will see other than "fail"; I've never encountered a failure to either one of those tests.

[Ratskrad]

Thanks - I ran the test again on the AC adaptor and Battery as you suggested - and both tests passed.

[snv]

If the system is ON and the power button is held for 5 to 10 seconds, it does a 'hard off'.

And, I assume, the battery light will be 'on' with the battery present, and the battery will continue to drain. That's tough... I feel that you are looking in the right direction then, but cannot help much.

Another idea: if you happen to have an X3 UltraBase, you could try to dock the laptop, plug the battery into the UltraBase, and see if the symptoms reproduce. My guess would be that they will, though... At least you might be able to exclude some traces on the motherboard from further troubleshooting.

[bobbarker]

The chip in the battery might be somewhat broken. When I tried to "refill" my X31 battery I had just about the same problem. I could pull up battery info, vendor, capacity, everything but it wouldn't put in or take out any current. Everything would indicate that the battery was being charged (even ACPI) but it just didn't work. You should try a different battery if you can find one.

[Ratskrad]

Hi Bob, Yup - tried a different battery and still no joy. The battery analyzer did 3 a complete CHARGE-DISCHARGE-CHARGE cycle, and showed that the batt still had around 80% of useful capacity remaining.

[Ratskrad]

Well, I have made some progress - finally found some SMD rework solder in Frys and have changed the Toshiba chip (TB62501F). The good news is that the swap went perfectly. The bad news is that the problem is still there!

hmm - now I guess it is down to testing the switching logic - ugh !