LG FFH-M217X Service Manual page 20

READING OK CHECK #A (= "NO DISC" DISPLAY)
A
DOES SL+ WAVEFORM APPEAR
AT
( IC503 PIN14 AND PN503 PIN3)
WAVEFORM #2
SLED MOTOR WAVE
DOES SLIN WAVEFORM
APPEAR AT
DEFECTIVE IC501
( IC503 PIN 5)
WAVEFORM #2
SLED DRIVE WAVE
DEFECTIVE IC503
DEFECTIVE PN503
CHECK PN503 CONNECTOR LINE
CONNECTOR
DEFECTIVE PICKUP
SLED MOTOR
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