Monday, August 15, 2011


In the first part of this repair report by Mr. Beh, he promised to come back with his final report of what he did next to the Grundig 21” Tv which refused to have high voltage even after replacing the fly back with a new one.

No doubt Mr. Beh is back with his final report on this repair …

Mr. Beh tells us we are listening…….. After I changed the fbt of this Television with a new one I expected the Tv to start working but the TV did not work and therefore I did not have high voltage yet.
This TV has an ic on the drive circuit and I decided to Google it and see what is it all about, the reference of this ic was TDA8140, after searching the net for this ic this is what I got.
The TDA 8140 is a monolithic integrated circuit designed to drive the horizontal deflection power transistor। And here is the application circuit for the same.

From the datasheet above you can see no doubt this is a very important component as far as horizontal deflection circuit is concerned because it is actually the driver circuit.
So I decided to change it and this time the TV has high voltage and I was happy but wait a moment, the picture came up but with a vertical line at the middle.

I started testing components on the same circuit and I found an electro cap in same circuit which was not good according to my meter and after replacing it the white line disappeared.

The Television is now happy and ready for collection by the customer.
Thank you guys.
God bless You
By Mr. Beh.... An Electronics repairer based at Tehran in Iran.