On September 19th, I signed on to AppleLink and discovered that my PowerBook 100 was being recalled [to prevent the problem that could melt a small hole in the case - see TidBITS-143]. That didn't sound good. I immediately called the 800 number, five minutes after closing time. "No problem," the person said, "we are here to help."
The next day, September 20th, Airborne Express delivered a big box to my doorstep, with complete and easy to follow instructions. I packed the PowerBook and the next morning called Airborne to come and pick it up, which they did the same day, September 21st.
On September 23rd, Airborne Express delivered the PowerBook back to me. Unfortunately, I couldn't get it to run off of the battery, just off of wall current. How did the battery get discharged? I left it charging overnight. The next morning (September 24th) it still wouldn't work off battery, and it wouldn't work off my spare battery. I called the Apple trouble line. John, who answered the phone, couldn't help, so he turned me over to Ben. Ben said, "you know that switch at the back of the PowerBook that disconnects the battery? Check its setting". "Oh," I said, flipped the switch and guess what, the dead battery came back to life.
Conclusion: A very smooth and well run operation. Nothing on the disk was lost. But I did lose all the Control Panel parameters - date, time, AppleLink setting - even the city setting in the Map. (Bad design, if you ask me: on battery-operated portables, this stuff ought to be saved on the hard disk, not in a power-sensitive location.)
[The trio of lithium batteries inside the PowerBook 100's "back door" provide current to store this kind of information, and even the computer's whole memory image briefly, when the main battery is dead or has been removed so another can be inserted. Under most circumstances, you'll never have ALL battery and AC power removed at once. This will only happen when the machine is being serviced, and all power MUST be removed so as to avoid damaging the PowerBook's components. Having to reset a few things such as time, location, and mouse tracking is, IMHO, a small price to pay in return for not frying the logic board. - Mark]
Disclaimer: Between the time I sent in the PowerBook and the time it came back, I accepted a job at Apple as an Apple Fellow to start 01-Jan-93 (where, among other things, I hope to improve designs such as the volatile Control Panel). My experience with the PowerBook modification was superb, but if it had been bad, I would have told you.