JVC QL-A2 Service Manual

7. Troubleshooting
7-(1) Platter does not rotate
Platter does not rotate.
ts22;05V
available at TP-5 when the
Power switch is
turned on?
Yes
No
Is a voltage
present at the
collector of transistor
X815?
Yes
No
Is an AC voltage present
, Yes
between lapping tabs 7 — 8.
No
Fuse or transformer dis-
connected. AC cord solder-
ing defective.
Transistor X815 — X817
or diode D809 defective.
Diode D810 — D813 open
or incorrectly soldered.
Hall elements open. Motor
disconnected inside, dis-
connected resistors.
Does the platter
rotate when R822 is
short-circuited?
Yes
No
Does the platter rotate
when pins 1 and 8 of IC 803
are short-circuited?
Yes
No
Does platter rotate
when emitter and collector of
transistor X803 are
short-circuited?
Does platter rotate by hand?
fs output available
at voltage terminals of Hall
elements HG-1 and HG-2?
Does platter rotate
when pins 6 and 1 of IC802
are short-circuited?
IC802 defective.
1C803 defective.
Transistor X803 is open be-
tween emitter and collector.
Transistors X805 — X812
defective. Lead from circuit
board to motor discon-
nected. Check for loose
socket, floating pattern and
defective soldering.
. Check for incorrect ca-
is the oscillation waveform pacitance or defective solder-
available at TP-3? ing of IC801.
1s diode D801 or
capacitor C808
not defective?
Yes
Replace defective part.
Notes for replacement of transistors X809 — X812
There are 4 ranks K1, K2, L1 and L2 for 2SD571 transistor
hfe. Be sure to use those transistors of the same ranking
when replacing.
Warning !
1. Be careful not to allow metallic dust, etc. to enter
inside the unit, be cause its motor is comprised of
magnetic elements.
2. After replacement of the X813 transistor, apply
KE45RTV (silicone adhesive) or an equivalent
material around the transistor for thermal con-
duction.
QL-A2
No. 2444

JVC QL-A2 Specifications

General

Brand	JVC
Model	QL-A2
Category	Turntable
Language	English