|Re: repair hp 27S calculator|
Message #2 Posted by Randy Sloyer on 30 July 2003, 12:48 a.m.,
in response to message #1 by Bob Plachta
Circuit cleaners are not the answer. Don't go there, as they can cause more damage, depending on the formulation.
It sounds like possibly two problems.
One, a loss of connection between the keyboard and logic board. This would explain the multiply and divide key behavior. After opening, you'll have to shim the foam pad that holds the keyboard connector against the logic board to solve this one.
Two, if it beeps and displays "Memory Clear" or "Machine Reset", you might have fractured solder connections on the 8k ram chip or a bad connection somewhere. It will take at least 5X magnification to see the cracks. Very subtle.
See the Rosetta stone of Pioneer opening here: http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/articles.cgi?read=5
Post again should you have any questions.
Edited: 30 July 2003, 12:49 a.m.