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ELECTRICAL TROUBLESHOOTING GUIDE
(1) No Power.
Any Key power on.
YES
NO Check power supply circuitry.
Is power turnd on? Q808, Q809, Q802, IC401, PIN13
YES
NO Check loading supply circuitry.
DISC loading? Q505, Q506, Q507, IC401, CN505
YES
NO Check laser circuitry.
Does initial reading occur?
Q501, IC501, IC503, IC504
Check focusing circuitry.
YES IC501, IC503
Check DISC.
NO Check tracking servo circuitry.
Can disc be played?
IC501, IC503
YES
NO Check audio circuitry.
Is audio output supplied?
IC501, IC401, IC601, IC801
YES
OK
- 2-6 -
(2) LCD light abnornal.
Any Key power on.
(without DISC)
Power supply circuitry
NO Check voltage in the power NO
Do display LCD then light? defective.
supply circuitry.
Q802, Q807, Q808, Q809
YES
Is u-com IC401 reset circuit
NO Reset circuit defective.
normal? Pin53
Q803,Q804 Surrounding
circuit defective.
YES
Is u-com IC401X1, X2 terminal NO
pin 57.58 input? X401, C410, C411 defective.
OSC : 7.2MHz
YES
Is u-com IC401 keyin Pin17, 18 NO Q807, CN802 front PCB
5volt input? pattern defective.
YES
Is u-com IC401 Pin45, Pin48
output waveform normal? NO IC401, Pin45~48 front PCB
pattern defective.
YES
Is IC901 Com1, Com2, Com3
output waveform normal? NO IC901, Surrounding circuit
PCB pattern defective.
YES
Display LCD connector defective.
- 2-7 -
(3) Initial reading is not carried out.
Slide motor moves NO Check the Voltage change of PN 505 NO Defective connector
PIN15 (7.5V) PN505
(Without disc)
YES
Check the Voltage IC 501 PIN12 NO
YES Defective IC 501
(1.4V~1.8V)
NO YES
Spindle motor turns Check the Data transmission from Defective connector
PN505 PIN7,8,20 to CD DSP NO PN505
YES (with disc) Defective MICOM
YES
Does RF waveform appear?
NO Check the Data transmission from Defective connector
IC501 Pin7
PN505 PIN19 to MICOM PN505
NO
Defective IC501
YES
Check the change of
NO Defective IC501
SLPWMF Voltage
(IC503 PIN23)
YES
YES Check the change of SL +,
NO Defective IC503
SL - Voltage
(IC503 pin 13, 14)
YES
Defective contact PN502
Defective PICK-UP
Laser light check A ?
Does FA+ waveform appear at
IC503 pin15? NO
focus coil drive wareform.
YES
Does TE waveform appear at
IC501 pin 11? NO
TRACKING ERROR wareform
YES
Is rotation normal?
NO
YES
Is there no dropout of RF signal?
Defective IC501
YES Defective PICK-UP
- 2-8 -
A When laser does not light.
Is "2.4V~3.4V" applied to pin 19 of IC 501?
( OV 3.4V 2.4V)
YES NO
NO NO
Did pickup return to Is data transferred from Defective MICOM.
innermost circular? MICOM IC ?
YES YES
Does voltage appear at IC NO
503 pin 13, 14? Defective IC 501, 503
YES Defective slide motor and/or
connector.
Does it stop at inner pick Is defect output from LMT
circular after shift? SW applied to pin 2 of
YES PN505? NO Defective LMT SW and/or
connector. (PN 502)
OPEN CLOSE
YES Defective MICOM.
YES
NO
Is power supplied to laser Q501? Defective connector. (PN 501)
(Q 501 collector: about 1.8V)
R555