(No.MB303)1-15
SECTION 4
ADJUSTMENT
4.1
Test mode
(1) Unplug the power plug.
(2) Insert power plug into outlet while pressing both "PRESET UP" key and "MIDLIGHT" key of the main body.
(3) Then, all segment of the FL display is blinking for 5 seconds, and tuner AM step is switching 9kHz.
(4) The high-speed of volume is checked by remote controller in the test mode.
(5) To release test mode, press "STANDBY/ON" key of the main body.
NOTE:
In the test mode, standby-LED is blinking for every 1 second.
4.2
Power amplifier section
Adjustment of idling current
Attention
This adjustment does not obtain a correct adjustment value immediately after the amplifier is used (state that an internal
temperature has risen).
Please adjust, after you turn off amplifier and internal temperature falls.
< Adjustment method >
(1) Set the volume control to minimum during this adjustment. (No signal & No load)
(2) Set the surround mode OFF.
(3) Turn
VR787
and
VR788
fully counterclockwise to warm up before adjustment.
If the heat sink is already warm from previous use the correct adjustment can not be made.
(4) For L-ch, connect a DC voltmeter between
B2204
and
B2205
(Lch) and, connect it between
B2213
and
B2214
(Rch).
(5) 30 minutes later after power on, adjust
VR787
for Lch, or
VR788
for Rch so that the DC voltmeter value has 1mV to 10mV.
* It is not abnormal though the idling current might not become 0mA even if it is finished to turn variable
resistance (
VR787
,
VR788
) in the direction of counterclockwise.
Measurement location
B2204
-
B2205
(Lch) ,
B2213
-
B2214
(Rch)
Adjustment part
VR787
(Lch) ,
VR788
(Rch)
Front board (L)
VR788
Front board (R)
VR787
B2204
B2205
B2213
B2214
VR787 (Lch)
B2204, B2205 (Lch)
VR788 (Rch)
B2213, B2214 (Rch)
