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CRT pinout for toshiba TV?

Have a toshiba cd35d60 with a green gun that sometimes doesn't fire -- the screen would turn magenta. Sometimes it cycles between normal and magenta while on. Poking the CRT neck circuit board with a plastic stick restores the green color, for a short while. It seems to be a bad contact.

I cleaned the pins on the CRT and put back the neck circuit board, but the problem remains.

Where can I find a pinout diagram for the CRT (model A89LFL50X02)? If I can identify the green cathode pin, then I can concentrate on it -- perhaps solder a wire from that pin directly to the neck board.

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Reply to
John
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If you'll put the stick away and get out a dc meter, you could find the pin yourself. Follow the collector of the 3 larger transistors to where they route to the socket. Blue on top right, green towards center and then red. When working, dc volts should be between 120 and 150. When the green is not working, then that pin should read between 180 and

200. My money is on a bad solder connection on the board itself. Of course, that's probably not near as much fun as hitting it with a stick and soldering a wire to the picture tube but, that's how technicians would normally go about it.

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Reply to
Tech Data

pin 5 G1 pin 6 Green pin 7 G2 pin 8 Red pin 9 filament pin 10 filament pin 11 Blue

According to the Sencore setup book.

Leonard

Reply to
Leonard Caillouet

Resolder all the joints on the CRT-PCB - intermittent dry-joints have become routine since manufacturers started using lead free solder, especially where there is temperature cycling like from the CRT heater!

Reply to
ian field

After reading the first two responses, I went looking for bad solder joints on the neck board and saw nothing obvious. I went ahead and resolder the joints starting from the green cathode pin to the driving transistor. Some of the joints looked suspicious (the solder bead up around the component pin), so I made sure the new solder spread.

I also polished the CRT pin (it turn blued) and applied a thin layer of solder to it.

After that, the TV has been working fine for two days. Can't conclusively say it is fixed, but looks promising -- previously it has never lasted more than 2 hours without losing the green.

Thanks to all who responded.

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Posted via a free Usenet account from http://www.teranews.com
Reply to
John

One of the features of lead free solder is that a bad joint can still look ok!

Reply to
ian field

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