HP42S - Display repair

[mfleming]

There have been a few discussions about replacing the LCD on a 42S, with observations about which calculators make suitable donors (like 17Bii) and variations in LCD models over time (try to get a donor produced around the same time as your 42S).

Have a look at the article Pioneer "Observational Internals" (article #5) in the old article archive here:

http://www.hpmuseum.org/cgi-sys/cgiwrap/...ticles.cgi

There is some good information on opening the case and removing the LCD. I found the article and others in the article list useful when replacing a "cooked" LCD display on an HP22S using an LCD taken from an HP14B donor. All you may have to do is replace the zebra stripes, in which case a donor in the same display class (131 by 16 graphic) as the 42S may be all you need.

Usual warning: Take care, work slowly, watch how much force you use on the LCD, and try to be as accurate as possible with alignment. I was delighted to see the new display light up properly on powering the calculator after the repair!