Happy to fix the 21 too. If it can be fixed, I'll do it...
May not be economical to repair though..
Jeff is dead right about the help you get here. Great bunch of ppl.
Luiz was able to tell me about the battery voltage for a
printer I got off ebay (believe it or not the service docs I had
didn't mention what it was). I thought it should be 6V based on the the charger output voltage but although I have 20 years plus experience in repairs, I did not want to GUESS when there are poeple here to ASK. Luiz wrote back in 90 minutes...
I now have my thermal printer running fine (still gotta do that paper feed roller, though...)
THE MAIN THINGS YOU SHOULD KNOW:
If you want to fix it (35) yourself, (1) get advice on disassemby
first and (2) get advice on and take steps to AVOID DAMAGING the
CIRCUITS WITH STATIC ELECTRICITY.
Cheers,
Don W
P.S. I had a friend in high school in the late 1970's who disassembled his 34C (then kinda state-of-the-art). On that machine
the chips are pressure connected (no soldering...[dumb]!) and when he got the case apart all the chips flew in different directions...
He never got it working again... He then bought a 41C...