Eastern Digital Co V700P, Руководство по обслуживанию

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6-9 POWER SUPPLY TROUBLE SHOOTING CHART
BEFORE CHECK SW.REG. PLEASE REFER TO THE POWER SUPPLY BLOCK DIAGRAM
POWER SUPPLY OUTPUT: (A)
VARIABLE OUTPUT : 67V - 168V
(DEPENDING UPON H.SYNC FREQUENCY)
(B) CONSTANT OUTPUT : 6.3V, 12V, -12V, 75V
BRIGHTNESS SET TO MAX.
THEN CHECK CRT G1 VOLTAGE ABOUT-40V
NG
NG
NG
LESS THAN 300V
NG
NG
OK
OK
OK
OK
OK
CHECK THE HIGE VOLTAGE
CHECK THE VOLTAGE OF CRT
HEATER ABOUT 6.3V
CHECK VOLTAGE OF THE CRT
CHECK BRIGHTNESS CIRCUIT
CHECK POWER SAVING CIRCUIT,
"ABNORMAL DISPLAY"
CHECK FAILSAFE CKT IC601
CHECK FBT. R846, C826
Q620, Q621, Q622 RELATIVE CKT.
REFER ITEM 8-2
CATHODE ABOUT 40V TO 60V
CHECK MAIN PC BOARD
CHECK SCREEN VOLTAGE ABOUT
400V TO 600V
Q707, Q708
PIN 2 RELATIVE CKT.
RELATIVE CIRCUIT Q705, Q706
CHECK CRT'S HEATER
OF CRT ABOUT 23.5 ~ 25.5KV
67V, 20V, 12V
7. 7. 7. 7.
MECHANICAL OF CABINET FRONT DIS-ASSEMBLY