I have a Sharp RPTV, model # 61R-WP5H, 61", about 6 years old.
For the past 6 months or so, it will work for random lengths of time. Sometimes 6 hours, sometimes 3 weeks. Eventually, the image will collapse & disappear into to bottom center of the screen, and the audio disappears about 2 seconds later. The power LED shuts off & the LED next to it (status?) begins blinking twice every 1.4 seconds.
Unplugging the set for awhile will make it come back, again for a random amount of time. Eventually it happens again. Lately it's gotten worse, lasting no more than 30 minutes before shutdown.
According to the service manual, 2 blinks every 1.4 seconds indicates that the "vertical output protector circuit" is not detecting any vertical output. Without this protection, the image would collapse into a single horizontal line across the screen.
Next to that, it shows a diagram of " IC501 " monitoring the vertical output as a 14V signal. The parts list in the back describes everything beginning with "IC" as an integrated circuit in the form of a chip or a voltage regulator. So my goal was to locate " IC501 " and find a loose solder joint somewhere in it's vicinity.
Problem is, " IC501 " doesn't seem to exist. It's nowhere on the indicated circuit board, nowhere in any of the schematics or PCB drawings, and nowhere in the replacement parts list. I've found other IC's with similar numbers (IC601, IC6501) but all are described as something different on the schematics.
The printed circuits on the board in question are large enough for me to repair with the soldering equipment I have. But it's a big board, and I just want to narrow down the location. Putting the PCB assemblies back into the set & reconnecting everything in order to test takes about a half hour, and I'd hate to have to do it more than once or twice.
Any direction would be appreciated.