Toshiba
Model: CF2750K
Chassis: TAC9011
Date: March 1991

Set is dead. Checked the basics like the input fuse and rectifier diodes and high wattage resistors in the power supply circuit.

Set has been worked on previously as caps in the vertical section were all changed and many solder joints have been reworked.

Jumped the power on relay and set came on, but the chnl up/down and vol up/down functions did not work.

Checked all my usual sources for tech data and no schematics or service literature could be found.

Anyone have any ideas or recommendations?

Thank you,

Lenny

Will set come on if you supply a 15kz signal to base of HOT ?

Check all caps,voltages and cold solder in standby circuit...it may be a problem in the start-up circuit...does it have voltage across the power relay?

Lenny, after you jumper the relay to come on, then push the power on button on remote. then you should have channel & volume control and any other normal functions again. whenever you just jumper the relay , tv will come on , but like you say there will be no remote functions until you push power on button. good luck Tom

Update:

Repaired the On/Off problem. Found Q863 leaky and QE05 open (2SC1815). Replaced with 2SC710 (ECG85). Set now works fine with power push button or remote.

Set has 2 other problems:

1. Set will not tune to any or receive any cable stations. It goes through the Auto-Program function, but does not receive any stations upon completion. It appears the tuner is bad. Voltage at the tuner pins is +32vdc and +5vdc. I'll be taking it out and inspecting it.

Connected to the rear external Video and Audio input jacks and the set did play fine when that input was selected...with the exception of no audio to the left speaker.

2. No audio to left speaker. Should be easy to trace with a scope.

Customer said set was hit with a power surge/lightening as many other items in the home were damaged as well.


Thanks to those who replied.

Lenny

Check for 6v or so at the AGC pin of H001=Tuner if absent trace it back to IC501=TA8680N=NTE7010 pins 1 & 2 if voltages are lower than normal replace IC501.I just worked on this unit with same problem:

20" Toshiba stereo tv model:CF2055A,chassis:TAC-9141,year:Dec 1992,Sams 2987,UL Listed:216V,has one set of RCA input & and ouput jacks.

Sidney
E-mail:sidneybek(at)yahoo.com
Dartmouth,Nova Scotia
Canada

I have a CF2750K Chasis 9011 and I only get half a picture. It's a clear picture, sound ok, tuning ok, all controls ok. The bottom half of the screen is black and the picture is only displayed on the top half. Any ideas?