The machine according to the remote control to change the channel, no character display, slightly increase the accelerating voltage, retrace line that line and field scanning circuit and imaging tube accessory circuit work normally. First measure sand Fort pulse, that is, IC601 (TAl215AN) 10 foot voltage, measured as 1.7V, and the normal should be about 0.7V, which shows that the pulse of sand castle. Check sand castle pulse forming circuit no abnormal, and then check the ABL circuit, that is, measured resistance caliber r850 (82k) at both ends of the voltage, one end of the B voltage, the other end to 0.45V, and this end is through the diode d557 (MA167 anode grounding to clamp, consider this machine for bus type color TV, should check the bus voltage is normal. To measure the bus terminal voltage of the CPU (MN1875876T5H), the foot {28} sda1 4.7V, 29 feet scl1 voltage 4.3v. Then test (scl1) voltage of the IC601{13} feet (SDA) and {14} feet, respectively 7.15V and 4.3v. Obviously {13} feet of the data line voltage is more than the normal working voltage. The CPU bus link in addition to the IC601 and dark balance adjustment of integrated circuit IC3401 (TA8889AP), measurement (IC3401) --- foot scl1 voltage 4.3v. {10} foot sda1 voltage for normal 4.7V, suspected damage TA8889AP, but will be replaced after the failure is still. Consider this bus is linked together, the voltage should be the same, this two lines for inspection, found to R631 between circuit breaker from the R3404, also from the R1134 to R631 circuit breaker, with wire connection, try machine fault exclusion.