sharp 21V-J70M yellow picture w/ sound then goes out in seconds

[egm]

to all,
 
Pls help me, when I turn on my sharp tv there is a yellow display with sound but it goes blue dark and cant see any more the image and also the sound gone. I have already replace TA8403 have also check Hor. driver and Hor. out but its ok. I will really appreciate your help thanks..

egm

[Turnip]

Hi there,

   Don't recognise the model, but yellow pic might indicate a tube fault. Sharp often used Philips tubes which tend to go cathode/grid (A1) short on one or other colour gun. Suggest giving the tube neck a gentle whack before it cuts to standby - might prove something.

   Good luck - Chris.

[egm]

Thanks chris,

I'll try it that way when I have time I'm in night shift sched this days I don't got much time yet..

rgrds,

ed

[egm]

hi

I have tried your advice but I got no response from the tube, I have tested some capacitors and diode but it seems all good what have I noticed that when it warms it turns to blue dark as well as the sound disappear. Thanks


ed

 

[Turnip]

Hi Ed,

    Just gave general advice as I couldn't relate the model number to a main board that I could recognise. Some additional info might be useful.

    Chris.

[amin]

dear friend
this occurs in Philps n the faulty is the tube,you better have a test done before going forward in changing parts.get a crt of same quality n plug the chassis to it u can seethe result.i have just change a crt of philips with the same symptoms.best of luck
amin

[egm]

hi amin

Thanks for the info it helps me a lot. more power....
til next time...

ed

[summersun]

MAYBE YOU CAN CALL AN EXPERT ABOUT TV TO HELP YOU.

[P.R.Gore]

Hi,
TA8403 is vertical O/P ic & it has nothing to do with blue dark raster. Check voltage at B cathode ,if it is low then fault may be of B amplifier circuit or B cathode getting leak with filament or G1. For B cathode short with filament, wind 3 to 4 turns of wire around FBT core, remove origional supply of filament from PCB, join two ends of newly wound wire to filament. Now ur tv will start working well without replecing CRT!!

[egm]

Hi,

Thanks for your help it works, perhaps this is a late reply one more thing, do you have links to download schematic and servicemanuals. Thanks again... more power...

egm