Jvc tv model av-56wp74 (by 2 users)

1024x768 Normal 0 Won’t start

The power supply has an automatic shutdown circuit that senses a shorted component and excessive current flow.

If you can access the convergence board and remove the plugs one at a time (red, blue or green) for the convergence output, the TV may start up and show a picture with the unplugged color misaligned.

This confirms a short in the convergence output. The convergence IC failure can show up as coloured outlines or power supply shutdown.

If this does not help, then there is some other short circuit in power or deflection circuits. You need a technician to troubleshoot HV or power problems.

Replacing the output amplifiers (located within the Convergence IC's) allows the pictures to line up correctly, and no more color outlines or power shutdown.

This is the most common fault in all makes of rear projection TVs.

Some models of TV require major disassembly and considerable shop/manufacturer's support to repair because of their design that causes other power supply or vertical deflection problems. The poorly designed products require a "bench" repair that can typically cost from $350 t0 $700.

Some TVs are designed for on-site repair and have more reliable circuit design that does not usually cause damage to other parts of the TV when convergence chips fail. The ones that usually allow reliable on-site repair are JVC, Samsung and Hitachi.

It is normal to have some resistors in the circuit burn up or increase in value from the heat (from 2.2 ohms to 5 or 10 ohms). These resistors must be replaced with the right value or the chip may fail again.

This is not a simple repair like changing batteries or a fuse. Reading through the other posts shows many that try and end up with bigger problems.

Your JVC uses STK 392-110 IC's. Misinformed people replace the IC's with other "new and improved" IC's, like STK 392-150. These are devices with different characteristics and require different value resistors in the circuit. Replacing with the STK 392-150 will cause overheating of the resistors and a damaged IC.

If you are in Calgary, I can help. If not, get someone that has experience working on your JVC. My website is below with some costs and explanation.

calgaryconvergencerepair.weebly.com/convergence-explanation.html

Good Luck,

Easyab