HP75D doesn't work with power adaptor



I have a problem with my HP75D :
It works fine with batteries but doesn't work with the power adaptor and doesn't charge the batteries.
I need the schematics because there is 11 volts dc after the rectifier bridge and nothing after the regulating transistors without battery and vbattery with.
Does somebody have an idea?
I will be happy to receive this schematics.

Best regards


Did you check the power adapter? Quite often the plug devlopes an open circuit. Connect a voltmeter and wiggle the wires around where they connect to the plug (machine end usually, somtimes at the wall wart)


Dear David,

Thank you for your answer.
I did tested the ac voltage delivered inside the HP75, not only at the adaptor. this voltage is unfortunately ok (i would prefer to have this kind of failure).



Dear Lucien,
I finally found my HP-75C Service Manual.
I'm scanning electrical plans.
Don't worry, be happy!
Regards. Yours.

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