Thinkpads Forum

I updated the BIOS of my 2645-910 yesterday (is a TP600). Got the correct firmware (as detected by the ActiveX application on Lenovo's site), wrote it to a floppy, and the utility told me the flashing had been a success (battery is brand new, and was running on AC). BIOS updates is nothing new to me.

To my surprise, the PC now prints 175 on the display and halts at POST. 175 apparantly means "EEPROM CRC #1 error.", and the suggested remedy is to replace the entire system board.

I've spent several hours googling on the matter, the most common EEPROM related problem with the Thinkpads seem to be a lost supervisor password, which can be retrieved by reading the 24RF08 chip (which on the 600 is called something similar, without the RFID functionality) - a CMOS that only seems to hold UUID, passwords and serial numbers and such. But there is no mention of the BIOS EEPROM itself.. what is this called? I don't suppose it's socketed?

I found is Joe in Australia who claims he can help me fix it for $90. But if I could do it for free, then all the better.

Most grateful for any help you can give me!

A CRC error is a huge obstacle. You can get a used motherboard on eBay for less than $90.

On startup, the BIOS runs. One of the first things it does is perform a couple of checksum verifications. It computes a hash on around half of the BIOS code, and compares that to what is stored in the security chip. If they don't match, it shows the 175 error.

To fix that, you need the correct number for your BIOS version to be stored in the chip. It's a hassle to do this outside the machine.

If you could put in a custom BIOS, you could skip this check, but then you'd never know if the BIOS were changed... and you can't do that now because the machine won't boot.

Bah.