Adjustment - Pioneer A-509R Service Manual

A-509R
6. ADJUSTMENTS
6.1 IDLE CURRENT ADJUSTMENT
¶ CAUTION : Heatsinks' (Q323–Q326) DC level is equal to +B or -B.
Don't touch them or you will be electricary chocked.
1. Connect the measuring instrument as Fig.6-1. (R415 or R416)
2. Set the VOLUME CONTROL to minimum, BASS TONE CONTROL to center, TREBLE TONE CONTROL to center and BALANCE CONTROL
to center. Set VR301 and VR302 to minimum.
3. Set the POWER switch to ON.
4. Adjust VR301 (VR302) so that the voltage between both sides of R415 (R416) becomes 16mV±1mV. (Within 10 seconds from when the relay
is turned ON)
5. Ages for 7 minutes.
6. Adjust VR301 (VR302) so that the voltage between both sides of R415 (R416) becomes 11mV±1mV.
24
DC Voltmeter DC Voltmeter
R415
R413
W150 W212
Heat Sink
VR301 R417
Heat Sink
Fig.6-1 Adjustment Method
AF ASSY
SIDE A
Heat Sink
R416
R414
VR302
Heat Sink
CN204