On Sun, Feb 25, 2018 at 1:45 AM, Sherry Haibara <v.castelli92@gmail.com> wrote: > 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. I've always been able to extract the boards from those monitors (and work on them) without desoldering the joke wires, one time I did remove also the CRT itself from the metal case, but usually the wires are long enough to allow the board sit just outside the case for probing and working on it. If you want to detach the joke wires, make a picture to be sure you reattach each wire where it belongs. Frank Message was sent through the cbm-hackers mailing listReceived on 2018-02-25 10:00:03
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