Daewoo KOG-261M, Service Manual

Page: 43 / 57

1 MP1 DC -5V±0.25 Replace ZD2, EC1, EC2 NO LOAD
2 MP2 DC -30V±1.0 Replace R21, ZD3 NO LOAD
3 MP3 DC -27V±1.0 Replace R21, R22, EC5 NO LOAD
NO.
MEASURE POINT
Fig. 6
WAVE FORM REMEDY REMARK
NO. CHECK POINT REMARK
1 IC1 PIN 6, 10, 11 -5VDC
2 IC1 PIN 1 -20VDC
3 IC1 PIN 22
4 IC1 PIN 8 OR 9
5 DP1 PIN 1& 25 2.4VAC (DISPLAY FILAMENT VOLTAGE)
1. CIRCUIT CHECK PROCEDURE
1) Low Voltage Transformer (DMR-604P) Check.
The low voltage transformer is located on the P.C.B.
Measuring condition: Input voltage: 120V
Frequency: 60Hz
2) Voltage Check
Key check point
CHECK METHOD
6–7 24V 30V
8-10 2.4V 2.5V
Voltage
Terminal
LOAD NO LOAD
43
PRINTED CIRCUIT BOARD
NOTE 1: Secondary side voltage of the low voltage transformer changes in proportion to fluctua-
tion of power source voltage.
NOTE 2: The allowable tolerance of the secondary voltage is within ±5% of norminal voltage.
NOTE: Each measure point must be measured with GND points.
T:16.67ms (60HZ)