Re: CBM 3032 (PET 2001N-32), no video?

From: Sherry Haibara <v.castelli92_at_gmail.com>
Date: Sun, 25 Feb 2018 05:40:10 -0700 (MST)
Message-ID: <1519562410288-0.post@n4.nabble.com>
Took a couple of measurements on the monitor PCB. The AC input is ok
(16.5Vac), but the voltage across the capacitor and on the LM7812 voltage
regulator seems to be very off. 
The voltage on the capacitor oscillates between 0 and 8.7 volts in a
rhythmic fashion (it goes like: 0-1-8.7-1-0). On the LM7812 (I assumed it's
the one mounted on the big heatsink right next to the capacitor) I measure
22V DC on two pairs of pins and 0V on the other. 
The 4 diodes on the bridge test fine with the diode test of the multimeter,
showing 0L on one side and a 0.55V drop on the other.



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Received on 2018-02-25 14:01:25

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