Toyota CRT2242 Service Manual page 24

GM-8886ZT ,8886ZT-91
ASL SECTION
Preset conditions
1. Set VR601 and VR602 around the center of the adjustable range.
2. Ground pins 3 and 16 of IC601.
Step Input
No. (MIC)
1 By using an oscillator, apply a sine
wave of 7Hz/3.6mV to the MIC
terminal (+) via a 600-ohm resistor.
2 By using an oscillator, apply a sine
wave of 7Hz/64mV to the MIC
terminal (+) via a 600-ohm resistor.
3 Repeat Steps 1 and 2 until doth adjustments satisfy the specifications.
4 By using the jig(CAN-906,CAN-912),
apply a sine wave of 7Hz/100dB-SPL Pin 22 on a digital
directly to the MIC.
5 End
To connect the Amp unit and the DSP unit, use Jig GGD1153.
TOP VIEW
DSP UNIT
24
Output
(Pin 22)
Observe the output at
Pin 22 on a DC V meter
(pointer-type).
Observe the output at
Pin 22 on a digital
multimeter.
Observe the output at
multimeter.
VR602
DC V meter
22pin
Digital multi
meter
VR601
DC Regulated
Power Supply
13.2V
SGND L+ R+
MUTE
BUS+ BUS- R-
ACC L-
CN903
CN903 CN902
AMP UNIT
Adjustment
Adj.point Spec.
VR602 1.3±0.3V
VR601 4.6±0.1V
VR602 3.6±0.1V
Oscillator
BOTTOM VIEW
DSP UNIT
13.2V
FL+ FR+ RL+
BU
GND TLMT GND FL- FR- RL- WF-
CN901
CN901
Conditions
Pin 16:Ground
Pin 3:Open
Wait for 20 seconds.
Pin 16:Ground
Pin 3:Ground
Pin 16:Ground
Pin 3:Open
600Ω
MIC
RR+
WF+ RR-