toshiba cf30c50 chassis tac9301

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ace electronics
toshiba cf30c50 chassis tac9301

cant seem to fid the manual its nla,,,plug the unit in and i get high voltage the shut down. nothing....i force the  relay on  and the tv works fine  sound  picture all good...looks like a  power on relay problem  but  i replaced jsut about  everything. it looked like a reset issue  i replaced  as many of the relay transistors  and the control ic,,,,,,any  help would be nice....

 

I CAN ADD ALOT TO THIS SITE I HAVE HAD MY OWN SHOP FOR 20YEARS AND WORKED AT SONY FOR OVER 10......This is the first ime i have used this site.....thanks

Silva
it might be a zener diode

it might be a zener diode some where in the power sup .

Larry Dillon
ace, have you measured the

ace, have you measured the voltage on the relay when you press the power?  If there is low voltage, check the capacitors in the standby power supply. If it is  there,  and one side of the relay coil does not go low, make sure the driver transistor that drives the relay is getting a turn on voltage from the microprocessor.  If there is no voltage on the collector of the transistor with the set in the off position, there is a problem in the standby power supply.  If there is voltage on the relay coil but the transistor does not switch when an on voltage is applied to the base of the transistor, the relay driver transistor is bad.  There should be at least .55 to .68 volts on the base of the relay drive transistor.  If  the collector and base have voltage on them in the off state the transistor is shorted or leaky.  With the set unplugged, measure the relay coil.  It should measure in the 10 to 50 ohm range.  BTW  Welcome to the site.  I am looking forward to your input on the questions., Feel free to answer any questions you may know the answers too.  Good Luck and if you need any more assistance, feel free to ask.  let us know if this helped you .

ace electronics
thanks for all the assist it

thanks for all the assist it was c863 in the reg. cir. i should have known it was a cap i put like 50 $$ into it oh well....thanks all

Larry Dillon
This problem almost all the

This problem almost all the time is a bad capacitor.  Glad you found it!

sliceorcutt
I have an intermittant

I have an intermittant vertical scan (deflection?) problem--quite regularly getting a solid horiz line when turning on.  Can I do this or better left for a repairman? Any help is appreciated...

Larry Dillon
If you have no TV repair

If you have no TV repair experience, play it safe and let a pro assist you in getting this repired. Good Luck, amd let us know how this repair turns out for you.

sliceorcutt
Repair was 145 bucks.  The

Repair was 145 bucks.  The vertical scan circuitry was replaced.  Don't know if it was difficult or easy for the guy but I'm happy as it was a free TV...now the picture is great!

 

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