LG TCH-800 Service Manual page 7

(3) Initial reading is not carried out (with disc)
DISC loading?
Does disc motor rotate?
Is RF wave output?
RF
NO
Is tracking servo operating?
Is the lower envelope of RF
waveform flat?
Is rotation normal?
Is there any irregularity in
frequency?
YES
Is RF signal normal without
dropout?
YES
Check voltage in the power
NO
supply circuitry .
Q505, R506, IC201 pin39, pin87
CDP PCB: IC301.
NO
Is IC201 pin21 input waveform
normal?
IC201
pin21
Does laser light?
CDP PCB: CON1 pin14(LD)
Is signal output at TEO?
NO
YES
Is signal output at tracking
output IC501 Pin 53 (CDP PCB)?
Does IC201 Pin25(LKFS) GFS
as figure?
NO
NO
Disc initial reading damaged or
defective.
NO
open close
YES
NO
YES
(B)
Is signal output at IC101
Pin50 (CDP PCB)?
NO
YES
NO
YES
NO
Disc defective.
- 2-3 -
Leaf SW contact defective.
Connector defective.
Pattern short.
(A)
NO
IC501(CDP PCB) defective.
Pattern defective.
IC502 (CDP PCB) defective.
Connector defective.
Pick-up defective.
IC201(CDP PCB) defective.