Watch the screen switch such as cross, disappear for a few seconds. I boot with DT830 digital multimeter to measure, no signal when it highlights the positive power supply 12 V circuit D633 normal elimination, Q630 b voltage of 11.9 V voltage of 11.7 V, e, c voltage 1.8 V, higher than normal. The C630 increases to 1000 mu F also of no help. t7sservice manual download site
 t7sservice manual download site
Will take off without Q630 desoldering temporarily, if shutdown variegation phenomenon disappears, highlight illustrate fault in the circuit, if shutdown variegation phenomenon still exists, explain the cause of the problem in the tube itself. Circuit board can be to get another try on 21 inches color tube. t7sservice manual download site
 t7sservice manual download site
 t7sservice manual download site
If is a tube failure, can consider to use electric shocks to repair method, but it is no good repair should be paid attention to when will damage caused tube completely discarded the bad consequences. Considering the variegation not especially bright and fault duration is shorter, the author thinks that also can not repair. t7sservice manual download site
 t7sservice manual download site
To inform the user, before the shutdown, to adjust the brightness for the biggest state to shut down, use of the machine itself function, the tube filament waste heat emission electron discharge rapidly, eliminate the phenomenon of shutdown variegation.t7sservice manual download site