Daewoo KOR-616T0P, Service Manual

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37
1. CIRCUIT CHECK PROCEDURE
1) Low voltage transformer (DMR-814FS) check.
The low voltage transformer is located on the P.C.B. Measuring condition: Input voltage:220V
Frequency : 60Hz
PRINTED WIRING BOARD
A
B
C
D
E
F
NOTE 1
: Secondary side voltage of the low voltage transformer changes in proportion to fluctuation of
power source voltage.
NOTE 2
: The acceptable tolerance of the secondary voltage is within ±5% of norminal voltage
NOTE
: Each measure point must be measured with GND points.
2) Voltage check
Key check point (MICOM PIN)
NO. CHECK POINT REMARK
1 PIN 21,24,32,33 OR 34 -5VDC
2 PIN 48 -27VDC
3 PIN 44
4 PIN 18 OR 19
5 DP1 PIN 1& 25 2.6 VAC (DISPLAY FILAMENT VOLTAGE)
NO. MEASURE POINT WAVEFORM REMARK
1 MP 1 -5V DC REPLACE Q4, EC2
2 MP 2 -16V DC REPLACE R6, EC3
3
MP 3 -24V DC REPLACE D12, D13, EC4
Voltage
LOAD NO LOAD
Terminal
C-D -19VDC -24VDC
E-F 2.1VDC 2.2VAC
T
5V
0V
T: 16.67 ms (60 Hz)
T
5V
0V
T: 250ns
CHECK METHOD