43
109B2 GS3 CM25
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Repair Flow Chart (Continued)
24. Selftest
check pin 24
1.no H/V sync & IF cable pin5 floating
- show msg.
2.H/V sync exist & IF cable pin5 to ground
- normal
3.H/V sync non-exist & IF cable pin5 to gnd
- power saving
4.connect a 15k resistor with IF cable pin5
- factory mode
5.connect a 5k1 resistor with IF cable pin5
- burn in mode
check idle status
sda=pin 25=hi
scl=pin 26=hi
25, 26. DDC bus
check idle status
sda=pin 31=hi
scl=pin 32=hi
31, 32. IIC bus
check key
Enter,+,-,bri,con keys
23. Keypad
check
pwm from 0V to 5V
38. Rotation
check
pwm from 0V to 5V
37. Brightness
check
7804 M24C08
7503 TDA4856
7304 LSC4378P2
7301 TDA4886
check
5V
5. Reset
check
active=hi
no active=low
22. Degauss