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

From: Sherry Haibara <v.castelli92_at_gmail.com>
Date: Sun, 25 Feb 2018 11:43:25 -0700 (MST)
Message-ID: <1519584205599-0.post@n4.nabble.com>
> the heater of the monitor is really independent from the main PET
> board. It should light as soon as you apply the AC power to the
> monitor PCB, even if no PET is connected. It's fed with the regulated
> 12V DC through a dropping resistor only.
> If it doesn't come on, there is no 12V dc on the monitor PCB or some
> connection is broken (wires going to the CRT neck, the dropping
> resistor, etc.)

The pins of the regulator seems indeed to be in a very sorry state. I'm
attaching a picture (let me know if it's visible). It looks like someone has
attempted to replace it but didn't do a very good job, those traces might be
broken at this point. How should the pins and the traces look like? Are they
supposed to be connected, and in what order? My guess so far is that the
left pin (top in the image) should be connected to the trace with the 'U'
shape, the right pin (bottom in the image) should be connected to the bottom
trace and the central pin should be connected to the trace on the left. 

After having applied some fresh solder to the pins, I now see 8V DC across
the two side pins and between the left pin and the central pin. There are 0V
between the right pin and the central pin. It sounds like the central pin
and the right pin are shorted together.

<http://cbm-hackers.2304266.n4.nabble.com/file/t374814/IMG_20180225_192003-02.jpeg> 




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Received on 2018-02-25 20:01:00

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