3-8
3. SERVO CIRCUIT
(1) Unstable Video in PB MODE
Does the Noise level of the
screen change
periodically?
Do the CTL pulses appear
at IC501 Pin76?
Is adjusting the height of
the CTL Head accurate?
Readjust the height of the
CTL Head.
Replace the IC501.
Refer to “When the Y signal
doesn’t appear on the
screen in PB Mode”.
Does the CFG waveform
appear at the IC501 pin67?
On tracking, do the CTL
pulses move?
Does the Video Envelope
waveform appear at IC501
Pin82?
Replace IC501.
YES
YES
YES
NO
NO
NO
NO
(2) When the Drum Motor
(2)
doesn’t run.
Do the DFG Pulses appear
at PMC01 Pin11?
Replace the Cap M.
Aren’t the foil patterns and
the Components between
IC501 Pin65 and PMC01
Pin11 shorted?
Replace the IC501.
Refer to “(2)
No 12VA of Power section”
Do the Drum PWM Pulses
appear at IC501 Pin34?
Aren’t the foil patterns and
the Components between
IC501 Pin34 and PMC01
Pin12 shorted?
Do the DFG Pulses appear
at IC501 Pin65?
Do the Drum PWM Pulses
appear at IC501 Pin34?
Are the connecting patterns and the Components
between IC501 Pin34 and PMC01 Pin12 shorted?
When the Drum Motor
doesn’t run,
Does 12V appear at
PMC01 Pin8?
Does 2.8V appear at
PMC01 Pin12?
Check the connector
(PMC01) and the Drum
Motor Ass’y.
NO
YES
YES
YES
NO
NO
NO
NO
NO
YES
YES
YES
VCR ELECTRICAL TROUBLESHOOTING GUIDE
Summary of Contents for RC-185
Page 1: ...SERVICE MANUAL LG RC 185 MODEL ...
Page 52: ...3 56 3 57 PRINTED CIRCUIT DIAGRAMS 1 VCR P C BOARD TOP VIEW ...
Page 53: ...3 58 3 59 2 VCR P C BOARD BOTTOM VIEW ...
Page 54: ...3 60 3 61 3 SMPS P C BOARD 4 HDMI P C BOARD HDMI MODEL ONLY TOP VIEW BOTTOM VIEW ...
Page 55: ...3 62 3 63 5 KARAOKE P C BOARD KARAOKE MODEL ONLY ...
Page 56: ...3 64 3 65 6 KEY P C BOARD 8 TOOL 9 TOOL 7 TOOL ...
Page 57: ......
Page 84: ...3 100 3 101 PRINTED CIRCUIT DIAGRAMS 1 VDR P C BOARD TOP VIEW ...
Page 85: ...3 102 3 103 2 VDR P C BOARD BOTTOM VIEW ...
Page 117: ......
Page 134: ...5 17 2 DISC SPECIFICATION 3 DISC MATERIALS 1 DVD ROM Single Layer Dual Layer ...
Page 159: ......
Page 160: ...5 42 5 43 CIRCUIT DIAGRAMS 1 DSP CIRCUIT DIAGRAM A B C D E F G H I J K L M N O P Q R S T ...
Page 161: ...5 44 5 45 2 RF CIRCUIT DIAGRAM A B C D E F G H I J K L M N O P Q R S T ...
Page 162: ...5 46 5 47 3 DRIVE CIRCUIT DIAGRAM A B C D E F G H I J K L M N O P Q R S T ...
Page 164: ...5 50 5 51 PRINTED CIRCUIT DIAGRAMS 1 MAIN P C BOARD TOP VIEW ...