7 Mar
2003
7 Mar
'03
9:18 p.m.
My (unexpanded) HP41c developed a strange problem...
It still knows how to do the maths, but any value stored inside a register
gets lost : i.e. 1234 STO 12, RCL 12 yields 0.000....
Any pointers ( also pointers to a more suitable group ? )
Jos Dreesen
7 Mar
7 Mar
11:10 p.m.
Jos,
You have a bad Data Storage IC. Depending on which version board is in your 41 it may
have from 1 to 4 DS ICs but they are custom built ICs made by HP specificly for the HP 41
so you'll never find one. Time to find another 41 for parts. There are plenty of htem
out there that have broken displays, bad power supply ICs and/or corroded battery
terminals.
Joe
At 12:20 PM 3/10/03 +0100, you wrote:
My (unexpanded) HP41c developed a strange problem...
It still knows how to do the maths, but any value stored inside a register
gets lost : i.e. 1234 STO 12, RCL 12 yields 0.000....
Any pointers ( also pointers to a more suitable group ? )
Jos Dreesen
8 Mar
8 Mar
9:56 a.m.
Jos,
You have a bad Data Storage IC. Depending on which version board
is in your 41 it may have from 1 to 4 DS ICs but they are custom built
Didn't some HP41s haev 5 RAM (Data Storage) ICs? Each one 16 registers
long (one for the 'status registers', 4 for the 64 user registers?
ICs made by HP specificly for the HP 41 so you'll
never find one. Time
A trick that works when you have a CV with one of the 'extra' DS chips
failed (that's to say one of chips that hold registers after the first
64), is to crack open a single memory module (which are really common!),
then extract the 'PCB' and wire it inside the 41, in place of the bad IC.
Solder the B3 and B4 lines to put it at the right address. Yes, it's a
kludge, but it works. And alas it's not applicable in this case.
to find another 41 for parts. There are plenty of htem
out there that
have broken displays, bad power supply ICs and/or corroded battery
terminals.
Perhaps I've been lucky, but I don't think I've ever seen a bad PSU chip
in a 41. Bad CPUs I've had, though.
Damaged battery contacts can be kludged over with a bit of care, so
that's not a reason to regard a 41 as a 'parts' machine...
-tony
7964
days inactive
7964
days old
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