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Problem: USB is not working or no USB Detection.

Check USB Supply, It should be nearly 5V. Also USB Enable should be logic high.

Problem: No audio at headphone output.

Check HP detect pin, when headphone is. Check 5V_VCC and 3V3_VCC with a voltage-meter.

Problem: Device cannot boot, TV hangs in standby mode.

There may be a problem about power supply. Check 12V_VCC, 5V_VCC and 3V3_VCC with a voltage-
meter. Also there may be a problem about SW. Try to update TV with latest SW. Additionally it is good to 
check SW printouts via hyper-terminal (or Teraterm). These printouts may give a clue about the problem.

Problem: No audio at main TV speaker outputs.

Check supply voltages of VDD_AUDIO, 5V_VCC and 3V3_VCC with a voltage-meter.

There may be a problem in headphone connector or headphone detect circuit (when headphone is 
connected, speakers are automatically muted). Measure voltage at HP_DETECT pin, it should be 3.3v. 

Problem: No signal in TV mode.

Check tuner supply voltage; 5V_TUN. Check tuner options are correctly set in Service menu. Check AGC 
voltage at RF_AGC pin of tuner.