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+--- Thread: HP41C s/n 1932A00199 (/thread-15759.html)
HP41C s/n 1932A00199 - Jose Gonzalez Divasson - 10-20-2020 11:03 PM
Hi,
I am now in awe, repairing a customer HP41c with serial number 1932A00199, together with a card reader 2029S45402.
When putting a different processor, the power off happens in 45 seconds instead of 5 min! Also the processor has a different texture to later units (even tall keys)
The top plate in the keyboard is nearly perfect too.
I am trying to post pictures but I can't...
[attachment=8811]
RE: HP41C s/n 1932A00199 - Diego Diaz - 10-20-2020 11:51 PM
Hi,
This is caused by the different display boards. Early units used a timer for the auto-OFF feature with a different capacitor (C2) value than those in the latter units.
You have to replace that capacitor in the CPU board, from 470pF to 10nF and you'll get the standard auto-OFF delay.
Hope this helps.
Best from Canary Islands.
Diego.
RE: HP41C s/n 1932A00199 - Jose Gonzalez Divasson - 10-21-2020 06:37 AM
Thanks!