The power light flicker-free, eliminate various adverse possibilities, general question may be: u5vservice manual download site
 u5vservice manual download site
Level 1, power panel power supply, or after load short-circuit CPU cannot complete detection, and without any test output. u5vservice manual download site
 u5vservice manual download site
2, the CPU itself, cannot be self-checking (i.e., D plate bad). u5vservice manual download site
 u5vservice manual download site
After electrify observation, boot instantaneous detection of the LED indicator light on the SS plate, SC plate detection of LED light is not bright. The judge P plate is usually normal, eliminate bad P plate. u5vservice manual download site
 u5vservice manual download site
For SC plate detection indicator light is not bright, SC plate work abnormal, SC light is generally bad itself in flashing, at a time when the power indicator light is not flashing, basic rule out SC board itself, SS plate detection indicator, suggests that D plate to the SS plate basic work. u5vservice manual download site
 u5vservice manual download site
According to the above analysis, doubt for SC plate driving signal received bad or missing. After further remove SC20, turns on. At this point, the measurement of SC scanning IC9006 level conversion, the input signal is normal, and no output, about 20 feet power supply only 1.8 V (5 V) for normal, basic determine IC9006 short-circuit fault. After replacing IC9006, the machine back to normal.u5vservice manual download site