Troubleshooting; Function Control Operation Test - Samsung QA65Q90RAK Service Manual

4. Troubleshooting

4-1. Function Control Operation Test

<Standby LED Status>
FUNCTION/IR Control Test
„
1. Place TV in Power Standby :
2. Check LED Status.
3. If LED is OFF
LED 1.7Vdc (pin 8) and VCC for 3.3Vdc (pin 3)
9
• If OK replace Function Assy.
• If Missing check Main Assy/Function Cable.
4. If LED is ON
Check " 5 Switch Operation Test Chart" for operation command changes.
9
P CMD
6 Center
7 Left
7 Right
7 Up
7 Down
< 5 Switch Operation Test Chart>
• If wrong or no change suspect a stuck switch which can hold data to Main Board preventing TV operation.
5. Check SDA, SCL for effective 3.3Vdc. (after power on)
6. Check IR with Standard Remote command changes. (3.3V to 2.5V effective DC)
Signal DC Voltage
Key 1 1.8V to 0 Vdc
Key 2 1.8V to 0.9Vdc
Key 2 1.8V to 1.3Vdc
Key 2 1.8V to 0 Vdc
Key 2 1.8V to 0.5Vdc
CN1501 (FUNCTION & IR)
1 IR
3 A3.3V_PW
5 SENSOR_SDA_I2C
7 KEY_INPUT2
9 IR_OUT_1
4. Troubleshooting
<To CN1501 Main Board>
<5 Function Switch>
2 IR_GND
4 SENSOR_SCL_I2C
6 KEY_INPUT1
8 LED_STB_OUT
10 IR_OUT_2
4-1