Failure, the detection STBY7V no output, T880 secondary no voltage output, check T880 secondary load without short circuit phenomenon, IC851 didn't work. At this point, the measurement of each foot IC851 voltage: 1 foot: 4-0 3:10 2-0 0 V V V V 5:5. 7 V 0 V at 7:30. JJ8service manual download site
 JJ8service manual download site
The voltage value, it is found that IC851:5 feet low voltage of 0.3 V, check 5 feet external parts, found C850 slight leakage, only the C850 removed after the detection of leakage resistance could be detected in RX10 gears at about 100 k. And the leakage is not stable, sometimes serious, sometimes leakage lighter. After replacing the capacitor, boot up OK.JJ8service manual download site