Maker Pro
Maker Pro

CRT pinout for toshiba TV?

J

John

Jan 1, 1970
0
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.
 
T

Tech Data

Jan 1, 1970
0
John said:
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.

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.

www.techdata-kicksass.net
 
L

Leonard Caillouet

Jan 1, 1970
0
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
 
I

ian field

Jan 1, 1970
0
John said:
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.

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!
 
J

John

Jan 1, 1970
0
ian field said:
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!

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.
 
I

ian field

Jan 1, 1970
0
John said:
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.

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