JBL Soundgear Series Service Manual page 11

A
Laser does not light.
Is "3.5V" applied to pin
YES
Did pickup return to
innermost circular?
YES
Does it stop at inner pick
circular after shift?
YES
Is power supplied to laser Q801?
(Q 801 collector: about 1.8V)
YES
Does laser current flow?
1.0V across R801
of IC 801?
70
NO
NO
Is data transferred from
MICOM IC ?
Does voltage appear at IC
803 pin
Is defect output from LM
SW applied to pin
PN803?
YES
YES
, ?
11 12
YES
of
2
OPEN CLOSE
YES
NO
R801 1.0V
R801 1.0V
-11-
NO
Defective MICOM.
NO
Defective IC 801, 803
Defective slide motor and/or
connector.
NO
Defective LMT SW and/or
connector.
Defective MICOM.
Defective connector.
YES
Defective Q 801 and/or laser.
YES
Defective laser and/or
connector.