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HP-80 display problem.
10-23-2021, 06:04 AM
Post: #5
RE: HP-80 display problem.
A pull-down resistor on pin 1 seems to solve (or at least mitigate) the problem. Now all I have to do is route it so that the calculator can still be put back together. The fit is a little tight.

The negative battery terminal has finally broken. It was severely corroded and hanging by a thread. I don't quite feel like stealing one from the 2nd 45 I'm fixing, so a kludge may ensue. Until then, AC adapter ho!

FWIW, the AC adapter with this thing was putting out half-wave rectified DC for the calculator not to run on. Opened it up and replaced the largest capacitor with a much newer one from my stock. Works fine after that.

Following my hunches seems to be working these days. Must be time to buy a lottery ticket, except that luck is conserved.

Reassembled calculator. Keys need cleaning; looks dirty next to the 45.
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Messages In This Thread
HP-80 display problem. - jlw - 10-22-2021, 06:15 AM
RE: HP-80 display problem. - teenix - 10-22-2021, 08:13 AM
RE: HP-80 display problem. - jlw - 10-22-2021, 11:49 PM
RE: HP-80 display problem. - teenix - 10-23-2021, 12:51 AM
RE: HP-80 display problem. - jlw - 10-23-2021 06:04 AM

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