Mini guide:
++++----- TV that doesn't turn on -----++++
1) Take note of signs of life and traces:
- If the standby light does a pulse code, try to find on web or manuals their meaning
- Burn marks, odd smells or noises
- Presence of bulging caps, if the tv is a led one, even their measurements are to be left on following steps because less probable , the capacitor plague is quite stuff of the past..
2) Power supply bench test. Measure the tensions of the outputs of the lonely board after putting a signal to turn the main stage on by sending a 3~5v on the enable pin (PS-ON / PWR-ON / STB / STBY), example, if the standby voltage level is 3~5v make a jumper to it and the enable pin, if the st.by is 5,xxV you can use a diode jumper with the catode to the enable pin, if more than 6v then make a resistor voltage divider, example , 13v----R1----En.pin----R2----0v, R1=3,3kohm R2=1kohm; after load the outputs so, 5v=5,6ohm 5W, 12v= car or halogen lamp max 20W, the resistor must heat and the lamp must fully glow.
3) If the power supply is correct and the pulsing led doesn't drive to another conclusion, there's an high chance that the standby memory is polluted, so first check its feedeing, if it's fed then rewrite the flash eprom / standby mpu, if not check where tension stops, so dc dc converters, smps or linear.
++++----- TV that doesn't turn on -----++++
1) Take note of signs of life and traces:
- If the standby light does a pulse code, try to find on web or manuals their meaning
- Burn marks, odd smells or noises
- Presence of bulging caps, if the tv is a led one, even their measurements are to be left on following steps because less probable , the capacitor plague is quite stuff of the past..
2) Power supply bench test. Measure the tensions of the outputs of the lonely board after putting a signal to turn the main stage on by sending a 3~5v on the enable pin (PS-ON / PWR-ON / STB / STBY), example, if the standby voltage level is 3~5v make a jumper to it and the enable pin, if the st.by is 5,xxV you can use a diode jumper with the catode to the enable pin, if more than 6v then make a resistor voltage divider, example , 13v----R1----En.pin----R2----0v, R1=3,3kohm R2=1kohm; after load the outputs so, 5v=5,6ohm 5W, 12v= car or halogen lamp max 20W, the resistor must heat and the lamp must fully glow.
3) If the power supply is correct and the pulsing led doesn't drive to another conclusion, there's an high chance that the standby memory is polluted, so first check its feedeing, if it's fed then rewrite the flash eprom / standby mpu, if not check where tension stops, so dc dc converters, smps or linear.