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

From: Sherry Haibara <v.castelli92_at_gmail.com>
Date: Sat, 24 Feb 2018 17:45:43 -0700 (MST)
Message-ID: <1519519543649-0.post@n4.nabble.com>
Thanks for the suggestion! Unfortunately I don't have a datasette to check
the CPU at the moment, I'll see if I can get my hands on one.

I did take some measurements on the video connector with the multimeter
though, and this is the result:
J1 (video signal): 4.47V
J3 (vertical drive): 4.26V
J5 (horizontal drive): 1.6V
I have seen that someone was mentioning on an old thread on vcfed that the
correct values for J3 and J5 should be around 4.6V and 1.8V, which don't
seem to be too far from what I've measured. The thread also mentioned that a
voltage greater than 4V on J1 is associated with a blank screen; the monitor
is indeed blank, though I can't say if that's because the monitor itself has
a problem or if it's not being driven correctly by the video circuitry. 

Incidentally, I removed the three screws from the back of the monitor and
I've noticed the cables of the yoke are directly soldered to the board; I
assume any reflow operation would have to be done with the CRT still
attached to the board? I know I'm a newbie, but I was also wondering how to
safely detach the monitor from the base and where should I look to remove
the top cover of the monitor assembly.



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Received on 2018-02-25 02:00:03

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