Strange message "Battery 2: Error detected"

[bartelon]

With the help of many great and detailed posts on the forum I succesfully converted my 15" T60 into a Frankenpad. I got hold of a 42W7872 board that came with the T7250 Merom CPU that I upgraded to the T9300 Penryn. With a 160GB Intel X25-M G2 (Middleton bios) and 4GB ram the Frankie was a real joy to operate. The T60 originally came with a LG SXGA+ IPS screen but I swapped it for a nice IDTech UXGA screen (worked straight away with no mod/EEPROM necessary).

About 3 weeks ago my Frankie went 'crazy' and developed a 'phantom battery'. The battery indicator started blinking orange and Power Manager showed the "Battery 2: Error detected" message although I have no additional tray battery. The main battery is detected and charged correctly. I tried to reset the 'phantom' additional battery but I got the "connect the charger" message despite the charger being connected. The main battery can be reset with no problems and no "connect the charger" message.

Now, it's not a software error as I initially suspected. The battery indicator blinks orange all the time, even after switching off the laptop, as long as the charger is connected. It only goes out when the charger is disconnected. When I take out the main battery, the indicator blinks orange the moment I connect the charger.

With all the symptoms it's definitely a hardware fault. Although I can operate the laptop without any problems both on the charger and the main battery (the only nuisance being the flashing orange LED), I'm perplexed and a little worried that the fault may became more severe over time.

I disassembled the laptop (the indicator blinks even on a bare board - no keyboard, CPU, memory, etc., only the LCD connected - as long as the charger is plugged in. Today I took voltages on several pairs of pins of the KBC (the chip responsibile for controlling most of hardware) and I2C Clock, data, voltage and temperature readings are the same both for the main and secondary battery (the main battery was disconnected).

I'm at a loss. Would someone offer any suggestion? I found an identical problem posted on the forum in 2007, concerning a T43 (http://forum.thinkpads.com/viewtopic.php?f=2&t=46105) but it remained without any answer. Any advice/help/suggestion will be much appreciated. I hope I will be able to enjoy my Frankenpad longer than several weeks.

[RealBlackStuff]

I would suggest first to try another OEM power supply.
Correct voltage is one thing, but if the electronics inside the charger are bad, results are unpredictable.

[bartelon]

Thank you for your suggestion RBS - I actually did that yesterday. Incidentally, the T60 came with a no name replacement AC adapter that shows as a "50W adapter" in Power Manager - despite being marked as a 90W unit - but I checked it only AFTER the problem began. Since it worked fine with the T60 equipped with the discreet Ati X1400 graphics vs Intel's integrated x3100 in my Frankenpad I didn't expect the PSU to be an issue. Anyway, the problem unfortunately remains on a a genuine Lenovo AC adapter...

BTW, I'm quite tempted by your LED backlighted Boe Hydis LCDs, RealBlackStuff, but that's another story and probably something for a PM. Not sure about shipping to Poland, though...

I'm open to any other suggestions regarding the fault. Could the KBC itself be at fault? In an act of desparation last night I connected the main battery to the secondary battery port by a crude but elaborate system of pins pulled out of an old scart plug but the orange flashing continued. Couldn't check anything else as it was done on a bare main board. I have a T61 schematics (I know open discussion on that is not allowed, so it's more for PM suggestions; apologies if mentioning this is not allowed either) and know my way round electronics repairs.

On a secondary note, while the Frankie is all disassembled I may try some hardware mods as e.g. described by Binh http://forum.thinkpads.com/viewtopic.php?f=29&t=106595. A potential problem with the described 266Mhz overclock might be a different clock generator on my board- it's an ICS 9LPRS319DKL for which I couldn't find any datasheets - only packaging info PDFs. If Binh is reading this I'd appreciate his input I couldn't communicate with the chip by RW Everything soft - it gives SMBus error... SetFSB can't communicate with it either

[RealBlackStuff]

I would stop experimenting until your battery/charger problems are sorted completely.

This is about a T30, but it may help: http://forum.thinkpads.com/viewtopic.php?p=406578

[bartelon]

I'm not experimenting, I'm trying to diagnose where the fault is... And I don't think the problem lies with the charger - as I said I'd already tried another charger (a genuine Lenovo AC adapter) and it doesn't solve the problem at all. Thanks for the submitted link but my problem is really different - the main battery charging circuit works with no problems whatsoever. The laptop also works on AC charger only, with the main battery taken out - while still falsely indicating problem with the 'phantom' secondary battery.

OK, maybe I wasn't clear in my previous posts so let me quickly sum up the problem:

1. The laptop works fine both on battery and on AC power; the battery is charged and shows its capacity, charging/discharging current etc., correctly.
2. The laptop falsely indicates there's a secondary battery present and detects an error with it (the message "Battery 2: error detected" in Power Manager under Windows); that 'phantom' secondary battery can't be reset in Power Manager as it then doesn't detect (falsely) the charger is connected. Upon selecting the main battery in Power Manager, the system correctly shows it's charge and all other parameters and it can be reset with no problem.
3. In addition to the Power Manager error message the battery charge indicator blinks orange that normally indicate a fully discharged (or faulty) battery. It also blinks when the laptop is powered off, as long as the charger is connected - hence my conclusion that it must be a hardware fault as the charging/battery LED indicator falsely indicates a discharged (faulty) battery even with no system loaded.
4. Since yesterday I've had a genuine Lenovo charger and the false battery error message still remains. My conclusion - it's not a charger problem, nor is it main battery problem as it still lasts about 3 hours and is charged correctly.
5. I could live with the Frankenpad as it is (the annoying flashing LED can be covered by black plastic tape etc.) but as I said I'm really curious what can cause the false error message indication and worried the problem may eventually get worse.
6. I described the steps I've taken so far to try to diagnose the problem. Nothing obvious so far - in addition to voltage measurements I already described I'd also measured the fuses in the secondary battery charging circuit and they are fine.

Would anybody have some further suggestions? I've run out of ideas and the only thing I can think of is a fault with the KBC controller chip (U23 on the schematic diagram) - but changing it would mean desoldering/soldering on a 144 pin chip and it's not for the faint-hearted , hence I'm hoping for other suggestions...