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HP-71B Chirp (solved)
09-17-2019, 06:15 PM
Post: #3
RE: HP-71B Chirp
According to your observations, the chirp happens each time the HP71 exits sleep state: key pressed, blinking cursor (software blinking), one-minute periodic battery-checking (when idle and no blinking cursor), end of DELAY.

It can be due to either software (bad configuration) or hardware (weak shortcut between a bus line and the speaker line, bad cpu i/o).

Can you check:
- check if any LEX file present, if yes remove them.
- remove any external modules (RAM, ROM, HPIL), does it change anything?
- check MEM and that the 4 internal 4k ports are not FREEd, if not CLAIM that ports. Any effect?
- Basic reset (INIT 1). Any effect?
- master software reset (INIT 3). Any effect?
- last resort, hardware reset: remove the batteries - at least one - and discharge the internal power supply. Remember to shortcut the supply lines not at the battery terminals but in the card reader slot, see here.

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Messages In This Thread
HP-71B Chirp (solved) - Sylvain Cote - 09-17-2019, 10:25 AM
RE: HP-71B Chirp - rprosperi - 09-17-2019, 12:29 PM
RE: HP-71B Chirp - J-F Garnier - 09-17-2019 06:15 PM
RE: HP-71B Chirp - Sylvain Cote - 09-17-2019, 06:57 PM
RE: HP-71B Chirp - Sylvain Cote - 09-18-2019, 03:05 AM

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