A22M 2628-P2u Error 0175

[Unknown_K]

So I got my first A series for the collection, a beat up 2628-p2u (should be a A22M) and I get the following error on boot: ERROR 0175 : BAD CRC STOP POST TASK.

From doing a brief google it seems that the CMOS chip is messed up? Is there any easy way to fix this?

[tfflivemb2]

I have a T23 that has that error, and from what I found at the time, there really isn't a way to fix it, without desoldering and replacing the chip on it.

[mediasponge]

I assume you've tried the routine about pulling the main battery, the backup battery, and pressing Power 30 times, then holding it in for 30 seconds? If that doesn't clear it, you're either talking about BIOS replacement service (soldering iron), or MB replacement. The info on the web at Lenovo and elsewhere indicates this is a fault in the EEPROM, not the CMOS. Google "0175: Bad CRC1, stop POST task" and all you'll see are discouraging words...

[Unknown_K]

Anybody have a picture of which chip needs replaced? Do you have to have it programmed before installing or can you boot from a floppy once the blank one is installed?

[frankiepankie]

I had that error on a A21m and i fixed it, but it was very difficult.

I believe the EEPROM that needed to be reflashed was the Atmel 24C01, but i am not sure, because it is a while ago that i did this fix.

I built an adapter to connect the EEPROM to the LPT port of my 2nd PC (i can vague remember the circuit used 2 zenerdiodes ).

Then i used some software to flash the dump from another A21m and *presto* it was fixed! But the modelnumber wasn't correct anymore (it had the type of the other A21) so i had to use the Hardware Maintenance Diskette to correct the type number.

This is all i know about, it is a few years ago that i fixed it.


It sure can be done if you are handy with electronics and programming.

[Unknown_K]

Got another system with the same issue (A21e this time), any chance you have the information to reflash that chip still?

[RealBlackStuff]

Loading a different (older first, then reload the latest) BIOS version should fix it, if you can get the floppy to boot.

[rkawakami]

With the 0175 error, the system will not boot any disk at all, be it a hard drive with an installed OS or a boot floppy. What the system is saying is that some data in the BIOS has been corrupted (checksum is not correct). It apparently was an issue with the older A2x and T2x systems. My understanding is that there was a critical period in the POST process, where if the system loses power, the data in the BIOS can be randomly altered. During each POST, the data in the BIOS is checked for validity and if any changes are detected, the 0175 error is displayed and the system refuses to boot. There were BIOS updates applied on these systems that should take care of this problem; look through the release notes of the BIOS README pages. The factory recommended way to fix it is to replace the system board. PM coming with full details.

ref: http://download.lenovo.com/ibmdl/pub/pc ... suku36.txt (A21e 2628 BIOS README file)

[Unknown_K]

Can I replace the A21E (15" LCD) MB with one from an A20M (14" LCD)? I assume the MB's are the same and the case was adjusted in size for the larger screen.

[ajkula66]

Motherboards between these are definitely not the same, but you might get away with your plan of attack...

Good luck.

[Unknown_K]

Did the swap, all seems fine (if I had a spare HD I could even load the OS). I assume if the video looks ok for the BIOS screen then there is no issue with the video.

Seems like the later A2* series has a heatsink extension from the CPU to the video these two didn't.