Mitsubishi CS2611R vertical problem.

[Lenny]

This set uses the LA7838. I did all the soldering and then took some
readings on the chip. Pin 1 VCC measures 9.0V, (according to NTE
should be 12V), and pin 8 measures 24V, (correct). Does anyone have a
database on Mits or have any tips on this model? Or perhaps if you
have a schematic you might be able to share with me or even just look
at to see what you think?
Thanks, Lenny Stein, Barlen Electronics.

 

[Asimov]

"Lenny" bravely wrote to "All" (30 Aug 03 09:42:43)
--- on the heady topic of "Mitsubishi CS2611R vertical problem."

I changed one on a Sansui not long ago. The pin 1 Vcc didn't seem to
mind being at 9v instead of 12v. If your top half pix is missing the ic
is bad. Change the small electro connecting to pin 9. A nearby diode
connecting to the electro should be tested. I think the NPN in the
output opens easily when the ic overheats. I had to strap on a larger
heatsink as the operating temperature had me worried. Good thing the ic
is cheap. Good luck!

LA7838
1 - +Vcc1 (+12V)
2 - vert trig in
3 - time constant
4 - vert amp ctrl
5 - vert size ctrl
6 - ramp generator
7 - vert out ac/dc feedback
8 - +Vcc8 (+24V)
9 - pump-up out
10- osc stop
11- ground
12- vert out
13- pwr supply for vert out


Le> From: [email protected] (Lenny)

Le> This set uses the LA7838. I did all the soldering and then took some
Le> readings on the chip. Pin 1 VCC measures 9.0V, (according to NTE
Le> should be 12V), and pin 8 measures 24V, (correct). Does anyone have a
Le> database on Mits or have any tips on this model? Or perhaps if you
Le> have a schematic you might be able to share with me or even just look
Le> at to see what you think?
Le> Thanks, Lenny Stein, Barlen Electronics.


.... No electrons were harmed in the posting of this message.

 

[Lenny]

It turns out that the problem was the chip after all. Thanks for the
response. Lenny Stein, Barlen Electronics.