Technics SL-QL5 - Troubleshooting Specific Symptoms

ae Arm motor ign Pe
Tusntable Power source circuit does not 1, Measurement of tonearm drive rope. Rope and belt Unstable FG amplifier circuit
not rotate 1. AC 18V between BT1 terminals 1.Power rotate 2.- Measurement of tonearm drive Pals: dislocation rotation 1. Conduction check of FG coil.
@ and ©. transform= 2. Waveform of terminal (3) of 1201. FG coil
2. DC voltage of regulator IC {I1C1). er, AC cord YES 1C201
® 20V, ® OV, @ 11.8V 21C1, $1 ae een R203, 205
3. DC voltage of regulator transis- D1, C1 C5 Arm motor control circuit po C201 ~203
tor (Q1). 3.01 D2 ons 4.5V
© 10V, © 5.6V, @5V maar 1. isnot at each terminal of 14ms
4. DC voltage at terminal @ of 4.10101 : =
(C101. (11.8V) ; 5.10201 @
5. DC voltage at terminal (8 of Stee 5 17 1417
1€201. (8.5V) 3 : re *
Lead-in 5 ce) 1.7 Quartz oscillator circuit
Return (0) 1.7+| 0 1. Waveform of terminals @) and @)
of 1C201.
Clock frequency 2. DC voltage at each terminal of 2.5V ment
1.
Connect
IC301
terminal
@
and
1C201
10401. STSTS | AY | 1
2.2V
terminal @. C204~205
eel
of
terminal
©
1C301
Stop:
Lead-in
|
1.3
|
3.8
|
3.8
1]
———
‘ Return 1 2.2 | 3.8 1. 1€301 0.238ys 1.9ys 0.1V
LIL 3. DC voltage at each terminal of 2. 1C401 Termynal ® Terminal @
za
bak
aiale
ia
rs
mores
ves|
Speed control circuit
1. Waveform of terminal (4 of 1C201.
RF1
* Stable * Slow * Fast
Push start switch, eed
(S301). Start/stop circuit
1. DC voltage at terminal @) of
1C301. (5V}
2. OC voltage at terminal Q6) of
1C301. (OV)
3. DC voltage at terminal (of.
C201. (OV)
4. DC voltage at terminal @) of
1C101. (0.6V)
Phase control circuit
1. Waveform of terminal (3) of 1C201.
*In-phase *Phase | *Phase |
p ag se lead 1¢201
| | 1C101
Drive coil and Hall element
1. Conduction check of drive coils.
(About 332) 1. Drive coil Lead-in return “ot . rot | | | | | |
2. DC voltage of Hall elements. 2. H101,HO2, defective with Arm position detection circuit
1C101
1
:
0
|
OT@TeT ee
[ Voltage | 3.8 | 7.6 | 3.8 | 9
PC601
no | !C401
ne gale oe 23 msec Offset angle
Drive circuit (Stop) does not Offset error angle detection
1. DC voltage at each terminal of | | | | 11V detection circuit
1C101
1¢101
1.
Waveform
of
terminal
@of
1C301.
@) | 8) a@~ a0! aD NO (During cueing down)
Voltage | 0 | 12 | 0 | 6
—
0.5ms
5V
YES
F 1.6
Cueing
ms
Drive
circuit
(Rotation)
down/up
Cueing
control
circuit
2.
DC
voltage
of
Q305
().
.
.
(1.8V)
1.
DC
voltage
at
each
terminal
of
does
not
1.
DC
voltage
of
1C301
terminal
@).
ar
ciiaueloumas
QSBe
3.0305,
306
bebe work (During cueing and down 0.8V.) . 5V C302
= @) ® a0 | @ 1 2. DC voltage of 1C301 terminal (@). 41C401
(Only during cueing down 1.6V.) 2.5V
[Voltage
|
0.8
|
4.9
|
4.9
|
4.7
|
3.
DC
voltage
of
0304
©
1.
1¢301
1.6
ms
a
2. Waveform between terminal @) 1C101 2. Q303, 304
and
(5)
(@and(@)
of
1C101.
NO
11.8V
aay
Piunger
4.
Waveform
of
terminal
of
1C401.
——
fa.sv
iV
Ty
33rpm .. . 303 Up Down
rpm
ms
<+——*
16ms
|