I have an IBM Thinkpad 600E that won't boot up. I used ctrl + alt + ins to boot into a screen with some diagnostic tools.

  • Memory test passes
  • HD test passes
  • SystemBoard test FAILS with Dev = 1 ERR = 91 and FRU = 3610

How can I diagnose this further?

diagnostics showing two passed tests and one failed

2 Answers 2


I was able to download the Thinkpad 600E service manual from this site. If I am understanding the info in the section "How to Use Error Messages" correctly, the

FRU = 3610

part says the first possible problem is the battery (36), and the second option is the system board (10). A failing battery on a 20+ year old laptop seems pretty reasonable. If you have the power supply, you should be able to remove the battery and try the test again. Leaking capacitors on the system board of a late 90s laptop would also not be surprising.

If this doesn't help pinpoint the failure, the manual also has a section for diagnosing "Undetermined Problems". The general procedure would be to basically disconnect everything that can be disconnected, external devices, battery, memory, cdrom and floppy drives, etc, and test again. If the error is gone, add parts back 1 at a time until the fault returns.

The manual also lists part numbers for diagnostic diskettes which might help you find a disk image that could be used to create the model specific diagnostic diskette.

Official Lenovo site in case of further issues with original.

  • 5
    I did a search when the OP asked his first question and discovered that the 600E was known for early battery failures! e.g., here at the thinkpad wiki
    – davidbak
    Commented Mar 7, 2023 at 21:14
  • 2
    Somehow that service manual site already seems to be offline, 11 hours after the answer is posted? Is there a more stable or official source for the manual's PDF for anyone else this applies to in the future?
    – Patronics
    Commented Mar 8, 2023 at 6:23
  • 1
    the "Hardware maintainance manual" is available on lenovos site: download.lenovo.com/ibmdl/pub/pc/pccbbs/mobiles/09n1033.pdf. The info you're seeking is on page 43+
    – Tommylee2k
    Commented Mar 8, 2023 at 8:32

I read somewhere else that it might be the little CMOS battery on the motherboard which probably went dead about 20 years ago :)

The problem is as I mentioned in the post. You get some cryptic messages when trying to boot so it's not obvious - but then... to be fair the diagnostics at boot did say my memory was okay and my HDD was okay and that it was a motherboard problem.

I replaced the 2025 button battery by removing 1 screw for the memory compartment to get access to the battery.

Windows 98 booted up!

Looking at this old laptop it is really an engineering marvel. So many compartments and options and doors and connectors. Really well made!

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