|Re: Hp 41 CX not turning on|
Message #5 Posted by Randy on 5 Jan 2008, 7:55 a.m.,
in response to message #4 by wildpig
This is all explained in the thread that you posted a link to but here goes again:
The CX has a 20 pin x 0.3" dip (1LF6-0001) along the right side of the board, it is the real-time clock. A 22meg resistor and a small round crystal are mounted below. The board is also used for the C and CV so if it is one of those, the board will be empty in those locations. If the board does not have those holes, with or without the components, it cannot be a CX.
I am considering direct wiring the cpu to keyboard as above
Once you start soldering wires between the logic board and keyboard, it becomes a throw-away unit. It is the worst possible solution you could ever implement. *Don't do it* as you'll never be able to test anything by exchanging parts.
Stated another way, if you don't know that all the parts are good before you solder the thing together, and then it doesn't work, you'll just end up pitching the thing in the bin.
Chances are that if the zebras were missing, you probably should consider the unit non-working. Using zebras from a good machine, swap a known good logic board into this one to test the keyboard and display. Once you know that is good, bring the old logic board back in and test.
All 3 cpu to keyboard interconnectors are gone
Only the two long strips of connections are used. The short group of four in the middle are not needed.
Edited: 5 Jan 2008, 9:05 a.m.