On Sun, Feb 25, 2018 at 1:40 PM, Sherry Haibara <v.castelli92@gmail.com> wrote: > 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. this doesn't sound right... The voltage from the input capacitor should show exactly on the input (left) pin of the LM7812 (measured with the center pin as ground) and if so, the right pin of the LM7812 should show 12V, unless it's broken or there's a short somewhere on the 12V supply. > 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. also carefully check the solder joints. Frank Message was sent through the cbm-hackers mailing listReceived on 2018-02-25 16:00:03
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