Technics SU-V90D

m MEASURMENTS AND ADJUSTMENTS
Control positions and equipment used.
@ Volume knob @ Remote speaker selector
@ Main speaker selector @ DC electronic voltmeter(EVM)
VOLTAGE CONTROL(V)AMP.IDLING(ICQ) ADJUST-
MENT :
1.Test equipment connection is shown in figure. (Connect
the DC EVM on both channels.)
2.Completely turn the (V) amp. adjusting volumes (VR401
, VR402) counter-clockwise.
3.Turn ON the set when it is cold, and immediately adjust
VR401 and VR402 so that the voltage is 25mvV.
Also, check that the voltage is 25 ~ 30mV (standard:
27mV) after lapse of 10 ~ 15 minutes. (Below 30mV af-
ter lapse of 20 min.) Unit
TPA=TP401, TPB=TP402
CURRENT DRIVE(C)AMP.IDLING(ICQ)ADJUSTMENT
1.Test equipment connection is shown in figure. (Connect
the DC EVM on both channels.)
2.Completely turn the (C) amp. adjusting volumes (VR551
» VR552) counter-clockwise.
3.Turn ON the set when it is cold, and after the adjustment
of the (V) amp. ICQ, adjust VR551 and VR552 so that the
voitage is 3mV.
Also, check that the voltage is 4 ~ 7mV (standard:
5mV) after lapse of 10 ~ 15 minutes. (Below 10mV after
lapse of 20 min.)
TPA=Z551, TPB=Z552
DA CONVERTER DC OFFSET ADJUSTMENT
1.Test equipment connection is shown in figure. (Connect the DC
EVM on both channels.)
2.Adjust VR853 and VR854 so that the voltage are less than 1 mV
in 3 mV range. TPA TPB
0)
Leh. Reh.
Unit
TPA=TP801, TPB=TP802
Note:
After replacing or repairing IC809-812 (Part No.
PCMS56P-J), rotate VR851 and VR852 fully clockwise
(to point C) and counterclockwise (to point A).
Afterwards, set the middle points between A and C to
their center positions (B).
@
VR851 and VR852
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