Switching Regulator Unit Output Error - NEC MultiSync 3D JC-1404HME Service Manual

2. SWITCHING REGULATOR UNIT OUTPUT ERROR
K1 ➔ 170V
K2 ➔ 85V
VERIFY PROPER VOLTAGE LEVELS
K3 ➔ 24V
NO
I'
NO OUTPUT ANYWHERE
I
1
Turn the power switch off and wait 30~60 seconds.
Disconnect CN-K connector and Insert dummy resister
so that rated current is added between K4-K 1, K4-K2,
and K4-K3. (Figure 1) Next, turn the power on and
check 170V, 85V, 24V again.
OK
NG
,
.
1
MAIN PWB or CRT PWB SWITCHING REGULATOR UNIT
REFER TO
ITEM (2-1)
FAILURE FAILURE
I'
Turn the power switch off and wait
30~60 seconds. Remove dammy resister
on CN·K connector, and connecting
CN·K connector again. Disconnect CN-X
connector. Next, turn power on and
check 170V, 85V, 24V again.
NG
Turn the power switch off and wait 30~60
seconds again. Then disconnect
CN-M connector. Turn power on and
check 170V, 850V, 24V again.
( Fig. 2-1 · 1)
Rated load current at K 1, K2, K3
170V
K1
85V
K2
24V
K3
R3
R2 R1
GND
K4
-29-
OK
- -
~
OK
NG
-
CN-X connector
CRT PWB
FAILURE
CN-M connector
SUB UNIT
FAILURE
MAIN PWB
FAILURE
RE FER TO
M (5-6)
ITE
RE FER TO
M (2-2) ITE
170V
65~290mA
(2.6kil~586.2il)
85V
24V
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35~230mA
(2.4kil~369.5il)
0.5~1.0A
(48~24il)