LG TL-AT130M - Manual (Page 21)

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SECTION3 ELECTRICAL
ELECTRICAL TROUBLESHOOTING GUIDE
5. SYSTEM/KEY CIRCUIT
(1) AUTO STOP
NO
NO
Does T/up reel pulse appear
at Q514 Base terminal?
Auto Stop
Does SW waveform appear at IC501
pin23?
YES
YES
Does T/up reel pulse appear
at IC501 Pin27?
Check Drum motor signal
YES
Is there 5.3V at RS501?
NO
Replace T/up reel sensor of deck
Check power circuit
YES
Check DP06, LP03
Replace IC501
NO YES
(2) No cassette tape loading
NO
NO
Is there 5.3V at IC501 Pin73?
Check IC501 Pin7, 8, 9, 10
No cassette tape loading
Is there REG. 12V at PMCQ1
Pin8?
YES
Does 'H' signal appear at IC501
Pin62 while inserting CST?
Check power circuit L104.
Check power circuit
Check D106, L103.
Check Deck mechanism
NO
NO
YES
YES
Check CST SW and peripheral circuit
YES
*Caution : Auto stop can occur because Grease or Oil is dried up