HP-25C Forgets steps in memory

[John Garza]

I've seen lots of talk about ACT chip failure, all very apparent. But this problem is a bit more insidious. Machine works fine manually, and even a program of say 5 steps or so will usually work. But in larger programs, occasional steps will be changed into GTO 00 and the machine will process them as any GTO 00 and stop. Could this be a flakey RAM chip?

Another interesting note: In another 25C, on clearing memory / changing batts, etc, program step 2 is GTO 02 instead of GTO 00 like all the other lines. But you can write over it and it will "stick" and work properly. The machine has been that way for at least 5 years and works normally otherwise and is perfectly useable.