5 V power supply abnormally elevated 0.4 V ~ 0.6 V, the upper right corner of the scope of jitter, serious when colour is out of step sound and sometimes without, the brightness much brighter than the first, occasionally machine can back to normal again. Failure indicator light flash 1 or 2, sometimes the reboot can work properly again. SGqservice manual download site
 SGqservice manual download site
From the failure phenomenon, repair the emphasis should be focused on the bus to hook up the related circuit (range is larger), and what causes control protection circuit. Starting with the principle of easy to difficult after, check the power supply voltage of all stripes have no obvious abnormality, change the DP board and DG box, fault as before; Using the suspect device heating/cooling is still not revealed point of failure. SGqservice manual download site
 SGqservice manual download site
 SGqservice manual download site
 SGqservice manual download site
Inspection IC1101 127 feet to PROTECT PROTECT the input of a failure to L level (normal voltage is about 1.8 V), the protection circuit has accused, for more protection monitoring terminal: 140 V over current/over voltage protection, filament over-voltage protection, ultrahigh pressure X-ray protection, field scanning positive/negative abnormal power supply protection, field scanning output work abnormal protection, 14 V over-voltage protection, CRT abnormal high pressure protection, etc. Complete protection, on the premise of no reliable protective, disconnect protection method is not desirable, but also in the maintenance must be on the premise of disconnection protection, is to clear the way to protect the accused, so as to find out fault source. SGqservice manual download site
 SGqservice manual download site
Off its links with the CRT, the whole circuit boards separately deflection coil, and the precondition of reliable isolation of high pressure cap, this time against suspected some disconnection protection check fault source. This case will protect circuit disconnect all still protect downtime. Touch 2.5 V / 3.3 V/V / 5 V / 8 and 9 V power supply IC, 5 V/IC2706 feel a little temperature rise, after replacing IC2706 still higher than other power supply IC temperature, measuring IC2706 2 feet of about 5.4 V output, detection of ground terminal respectively selected in IC2706 3 feet and high frequency grounding end, measured 5 V output have obvious difference, the result IC2706 3 feet is through a patch of grounding device, check the tiles have unstable resistance.

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