Samsung CL21K40MQGXXAZ Service Manual page 39

Troubleshooting
3. External Input Diagnosis
This consists of AV1/2 and Component signal inputs as well as monitor output (Video, Audio).
The signals are sent to UOC and the selected signals are output.
If the signal input or output does not work, check the following items.
- Check for input defects: Check the Micom input pin.
- Check for output defects: Check JA701A (for RF/AV) or JA702(for comp)
Samsung Electronics 6-7