Tv picture has a bow in it and letters are doubled
I have a 51" hdtv magnavox rear projection tv n one day the tv went all blurry n it bowed on the top and bottom. I adjusted the convergence and the picture is good again but it still bows? How can I fix this?
You also need to check the resistors, they usually go first , causing the STKs to fail.
I have a service manual PDF if interested
Here is the link for the service manual
http://www.mediafire.com/?ad1mtycjei3
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Try re-soldering the circuit board that contains the STK convergence modules. They're on the center circuit board attached to an aluminum heat sink that's about 8" long and 6" tall, about dead center in the circuit board. You may be able to recreate the problem (hour glass effect) by gently moving the heat sink (which the modules are connected to). This gives the hour glass effect on the picture and the advanced convergence screen. This is an indication that the modules pins aren't solidly connected (meaning soldered) properly. Remove the circuit board and clean the old solder off & resolder the modules pins to the circuit board reconnected the board and then retest by again pushing on the heat sink. This is a caused by a minimum effort (a.k.a. minimum cost) solder job, probably done in some 3rd world sweat shop. The "factory" job was good enough for 3-4 years but the heat (and these modules do create a lot of heat) and stress created from repeated use eventually takes it's toll, weakens the pin connections and our problem occurs. take the appropriate cautions working around the high voltage of the set & use a non-conduting piece of wood to push the heat sink when we doing tests. Best of luck, hope ya fix it.
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thank you so much for the help and info! i appreciate it!
Changed my stk392-120's ic's and it won't turn on just blinks at power button.a burned area on bottom of heat sink,looks like where it connects to board.ic's didn't look bab but changed anyway. Jeff
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