Thursday, January 12, 2012

Handycam CCD-F370E mini crt

Short story: I have a Sony videocam bough some years ago but I think I never recorded anything with it, it was bought second hand and for some years it worked, I mean, I could see the lens image on the viewfinder but it stopped working some months ago, the camera can't focus anymore and I have only what looks like out of sync in the viewfinder, probably some cap leaked and or out of specs.
Since I never used the camera and there are less bulkier and digital alternatives nowadays, why not open it up and remove some components; being the most interesting parts the microphone, the lens and the view finder. Specially the viewfinder looks interesting to make a tiny oscilloscope (while I don't fix my broken scope) or an ATV video monitor.

Now on to dis assembly:

The viewfinder part...

After searching I found some people in the same path but no detail on pin out for the minicrt, so, on to some reverse engineering.

It took me some 10 minutes to find the connection pinout, just to discover the crt would not give image although the record led (connected to the crt control board) indicated power. I increased the voltage to test on 9V (was using 6V and is correct). Nothing! Bloody hell! I hate reverse engineering!
Stopped and waited some time, then returned and had another look just to discover my fault, I was biasing the power the wrong side, I mean I thought the led was switched by the positive but instead is the negative (cathode, anode is always connected to +), it also helped tracing a big coupling cap connect to the only IC in the board (it had to have power directly connected so easy to trace to power line)..... "et voilá", the thing works but I still didn't connected any signal to the board.

The small component near the crt in the following image is an 1W zener.... it's really small the crt but with the lens it's easy to view.
Now the pinout:
After all this work.... if I had just looked bellow one cap I had noticed that there was an video IC bellow it.... if I looked on the IC datasheet I had easily found the pinout, live and learn! Now I have to trace deflection coils to the AN2512 ("Electronic View-finder driving IC") to make tests on deflection.

Now the lousy video:


Have fun!

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