This machine has no signal muting and the blue screen function. If the image channel failure will also cause no sound phenomenon; showed a black screen after changing channels, shows no video signal after a blue screen, indicates that CPU on behalf of radio signal is detected at the end of the corresponding information. AV Terminal input signal properly, explains after the TV/AV switch of the channel and the audio circuit without a glitch.

The AV/TV switching circuits by ICl401 (M51321P), (see Figure 5). Starting from ICl401 TV video input check voltage measurement from back to front. Q1403 c measuring voltage is only 4. 3V (normal value is 11. 3V), insurance R1413 top measuring voltage 12V normal power R1413 ends DC resistance value measured on the road after about 220 ω, resistance increased significantly. R1413 troubleshooting after replacement.