family friend's IBM T21 problem

This problem bugged me since last year.

The error is 0175: bad CRC1, stop POST task.

Thinkpad T21, yeah, is fine piece of art.

I told my family's friends that the BIOS chip might be fault or corrupted.

Then family friends bought a bios chip from CN.  on the top of the chip:
30L2412 rev 49, (C) IBM 00, T2602

a google search turned out this is for T23.

I started to dismantle the T21. well the bios chip is actually under the memory modules.
Intel flash
08K3976
REV 15
T5200

google search indicated this model is for T20. anyway there is little more I can do to help.