Sound Signal Circuit between Stereo Component Tuner Assembly and Television Display Assembly: Procedure

1. Disconnect the L18 stereo component tuner assembly connector.
   Fig 1: Checking Stereo Component Tuner Assembly With L18 Connector End View

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2. Using an oscilloscope, check the signal waveform between each terminal and the body ground according to the conditions, as shown in the chart below.

   Signal Waveform

   Tester Connection	Condition	Specified Condition
   L18-10 (FRI+) - Body ground	Audio sound is being produced	A waveform synchronized with sound is output
   L18-9 (FRI-) - Body ground
   L18-8 (FLI+) - Body ground
   L18-7 (FLR-) - Body ground

   TEXT IN ILLUSTRATION
   
   

   *1	Front view of wire harness connector (to Stereo Component Tuner Assembly)

NG → See step   2 

OK → See step   3 

1. Disconnect the L18 stereo component tuner assembly connector.
2. Disconnect the U1 television display assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   U1-9 (R+) - L18-10 (FRI+)	Always	Below 1 Ω
   U1-10 (R-) - L18-9 (FRI-)	Always	Below 1 Ω
   U1-23 (L+) - L18-8 (FLI+)	Always	Below 1 Ω
   U1-24 (L-) - L18-7 (FLR-)	Always	Below 1 Ω
   U1-9 (R+) - Body ground	Always	10 kΩ or higher
   U1-10 (R-) - Body ground	Always	10 kΩ or higher
   U1-23 (L+) - Body ground	Always	10 kΩ or higher
   U1-24 (L-) - Body ground	Always	10 kΩ or higher
   U1-25 (SLD9) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   4