Saturday, March 17, 2012

HDTV Repair

Who says you can't repair televisions anymore?  Well, it is getting more and more difficult to do these days. 

We have an aging (maybe 6 years old) 52 inch HD projection television that spazzed out last week.  The image overlaps and the three primary colors appear seperated.  It kinda looked like 3D TV without the glasses.  Thank God for Google cause I did a search on those symptoms for our RCA model and sure enough up pops a well known problem with the convergence circuitThe problem is well documented and is easily corrected by replacing fuse FL231 on the circuit board that houses the flyback transformer and the convergence circuit.

So I ordered the new part and the instructions and they arrived in just a few days.  I got the opportunity to do the repair this afternoon.  Pretty simple to remove the back cover, disconnect all of the cables and connectors on the circuit board, pull the circuit board out, turn the circuit board over, desolder and remove the bad fuse, install and solder the new fuse, re-install the circuit board, reconnect all cables and connectors, replace the back cover, and power the TV back up. 

Back up and running in about 40 minutes or so.  Sure beats paying someone else to do it or throwing it out and buying a new one!

About to begin the operation

This is the circuit board with the convergence circuit

Fuse FL231 is the one in the middle.  It's a 400mA fuse.  If it opens (blows) then there is no convergence of the primary colors.

FL231 is now removed

The new FL231 fuse is now installed

Here is the bottom of the circuit board before I soldered the leads of  FL231.

And here is the culprit of non convergence!