This is actually is response to a month-old posting, which came up on google; the problemees have likely effected some kind of fix

You have, of course, kept your finger on the f1 key, and gone to the dialog which TELLS the 770 to boot from the cdrom, right? If you have noe luck, a desktop adapter is a good way to install Linux on this machine. I have lost cdrom boot capabilities by putting in the wrong cpu;

This is pertinent to the guy with the 173 error, (I'm ignorant) although I'm shocked that he didn't get rid of the 161,163 errors by replacing the coin batt- maybe clean stuff or try another one.

I put in a pentium II 266 in the 770 (with the mmc-1 socket, which has two rows.)On boot

you get an error, which can be discarded by pressing esc. Then a scary error with a slash through the icon comes up which can be dispatched with the f1 key. I've looked at firmware sites to see if anyone knows about hacking the bios upgrade code, but it's not that compelling , and those guys are all about cd-dvd-burners anyway.

The esc, f1 keys don't seem to work on clock battery errors, though.

Here an answer from a Thinkpad 770 user!

The 161 163 error is a very common error on these machines as I have found out.
Many people on the net have the same error.
With these errors your Thinkpad is useless.

Any other cheap mainboard will boot even if you remove the CMOS battery but the Thinkpad WILL NOT!

When replacing the CMOS battery doesn´t work the only solution (if you look at the parts and error list at IBM)would be to replace the system board.

Buying the original part is a ridiculous option (too expensive) so I left my 770 lying around for more than a year.

A few weeks ago I bought a second hand Thinkpad (only the body with internal parts) for 75 Euro.
After several complete strippings and rebuildings I finally fixed the 161 163 error!

Replacing the system board was really the only solution.

After so much effort now I have another big problem:

The original harddisk is locked because it got its password from the original mainboard (which is dead).

If someone has a (do it yourself) solution for a locked IBM harddisk please post it here.
I guess no one has a solution because I have read much about it in other forums and its never solved until now!

Now I will buy a second hand laptop harddisk and hopefully i will have a fully functional 770 again.

The final conclusion for me after all this is that I would never buy a new IBM laptop.....

I have found another (maybe the biggest) problem on the Thinkpad now and hopefully someone has a solution:

THE THINKPAD 770 RUNS VERY HOT(OVERHEATS?)

The fan only runs at startup, but after that it doesn´t seem to start resulting in a very hot harddisk and other parts.

There must be some thermal switch that is not functioning well I guess.

If this occurs on other Thinkpads too please post it here because maybe this overheating is the main reason why the system board gets damaged resulting in error 161,163.....