This type is bus control circuit complexity, check the power supply section of the three-terminal regulator chip IC805 (AN7809-LB) input current limiting resistor R842 resistance increases, making the IC805 input voltage drop is about 8V, the output voltage drops to about 7V. 8842 icon value is 4. 7 ω/5W (icon value is 2. 7 ω/3W), fails, R842 turns ranged from more than 10 to more than 20 European, bigger failures more serious resistance. Using the same resistance after the replacement, troubleshooting. R842 variable value is the resistance of fever caused by severe because the R842 following printing plates has become yellow and black.

IC805 voltage regulator 9V output voltage for the chrominance signal decoding, after scanning chip IC601 (TAl215AN) power supply, as well as baseband IC603 1H delay line (TA8772AN) power supply, due to its power supply voltage is too low, does not work properly, causing the fault.