Main Pwb +Bline Failure; Line Failure - NEC MultiSync 3D JC-1404HME Service Manual

(2-2) MAIN PWB +Bline FAILURE
Remove MAIN PWB from chassis-then
You should check following +Bline loads.
(2-2-1) +24V line load
(2-2-2) +85V line load
(2-2-3) +170V line load
(2-2-1) +24V line FAILURE
Apply +24V DC between K3 and K4,
(using external DC Power Supply Unit)
CHECK +24V line voltage
NG
'
OK
CHECK
NG
- : V. DEF OUT FAILURE (IC402, 0403~0405, etc.)
-
V.DEFOUT
OK
'
CHECK +18V line
MEASURE BETWEEN TP502 AND GND
voltage
+18V REG FAILURE (0530, 0531, ZD511, etc.)
NG H. F/V FAILURE (IC155, IC157, IC507, 0505, etc.)
OK
-
H. PHASE CIRCUIT FAILURE (IC155, IC501, IC502, 0501, 0502, etc.)
MEASURE TP550 CHECK
NG
+12V line -i.
CHECK C522 VOLTAGE HEATER PROTECT CIRCUIT (R536)
NG
(22V~23V)
-
OK
i
OK
I
T_.; I
...
I
CHECK H. OSC OUTPUT
1SL"'"T"40kH,
0506 EMITER
9
I
OK
CHECK
SAW TOOTH GENERATOR OK
tNG
NGi
I
H. OSC FAILURE (IC401, 0506, 0507, etc.)
I
SAW TOOTH GENERATOR +12V REG. FAILURE (0519~0521, T501, etc.)
FAILURE PARTS OF +12V LOAD ARE FAILED
(0514~518, etc.) (IC152, 156,501,403, 0401, 406,510, etc.)
OK
'
+5V REG OUTPUT ERROR(•>
CHECK OK
CHECK
NG
+5V REG FAILURE
+5V line
DIGITAL CONTROL CIRCUIT FAILURE (IC151~IC153, etc.)
OTHER LOADS
AFC FEEDBACK CIRCUIT ERROR (IC508, etc.)
(+85V, +170V)
(•) If short mode at +5V line has occered, you must check lmpeadance of R567. (8.2Q 3W)
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