SERVICE MANUAL
MODEL
AVR-2105/885
AVC-1890
AV SURROUND RECEIVER / AMPLIFIER
Tokyo, Japan
X0206V.01 DE/CDM 0407
For U.S.A., Canada, Europe, U.K.,
Asia, China,Taiwan R.O.C., Korea
& Japan model
Please use this service manual with referring to the
operating instructions without fail.
Some illustrations using in this service manual are
slightly different from the actual set.
For purposes of improvement, specifications and
design are subject to change without notice.
2
AVR2105/885 / AVC-1890
SAFETY PRECAUTIONS
The following check should be performed for the continued protection of the customer and service technician.
LEAKAGE CURRENT CHECK
Before returning the unit to the customer, make sure you make either (1) a leakage current check or (2) a line to chassis
resistance check. If the leakage current exceeds 0.5 milliamps, or if the resistance from chassis to either side of the
power cord is less than 460 kohms, the unit is defective.
(1)
(2)
500V
1M
(1)
(2)
3
AVR-2105/885 / AVC-1890
LEVEL DIAGRAMS
FRONT/CENTR/SURROUND/SURROUND BACK
+
DIR
DSP
D/A
D/A
D/A
6dB
MUTE
--
+
D/A
HPF
MUTE
+
0dB
6CH IN
10dB
20dB
30dB
40dB
6CH IN
0dB
10dB
20dB
30dB
40dB
6CH IN
CD IN
-12dB
---
-30dBFS
-10dBFS
0dBFS
A/D
A/D
-30dBFS
-23dBFS
-20dBFS
-10dBFS
0dBFS
-30dBFS
-20dBFS
-10dBFS
0dBFS
+--
-15dB
15.5dB
15.5dB
MUTE
25.5dB
25.5dB
-35.5dB
ATT
6CH IN
DIGITAL
6CH IN
CD IN
A/D IN
REV AMP
A/D IN
REV AMP
-20dBFS
+
D/A OUT
70.8mV REF
6dB
6dB
D/A OUT
100mV REF
+
D/A OUT
LPF
REV AMP
SURR/SB
CENTER
SUM S/W
SW SUM
REV AMP
VOL 00
MUTE
POWER AMP
D/A OUT
100mV REF
-20dB
-10dB
-20dB
-10dB
TONE CONTROL
-18dB
H/P OUT
(200mV)
(200mV)
FRONT
A/D IN
REV AMP
INPUT
BUFFER
AMP
DSP OUT
-18dB
VOL 00
PRE AMP
SPK OUT
FRONT
2.83V
(1W/8ohm)
CENTER
SURROUND
SURROUND BACK
SPK OUT
CENTER
SURROUND
SPK OUT
2.83V
(1W/8ohm)
H/P OUT
47mV
(0.27mW/8ohm)
SPK OUT
FRONT
4
AVR-2105/885 / AVC-1890
SUB WOORER
OdB
D/A
LFE
--
+
D/A
LFE
6dB
MUTE
MUTE
6CH IN
-30dB
-20dB
-5dB
30dB
DSP OUT
-20dBFS
6dB
+--
VOL 00
21.5dB
-10dB
20dB
10dB
-30dBFS
-10dBFS
0dBFS
Front D/A Out
100mV ref
D/A OUT
LPF
REV AMP
SW SUM
REV AMP
SUB WOOFER
PRE OUT
SUB WOOFER
PRE OUT
373mV
(112mV)
(200mV)
Config1 -38dBFS
10.5dB
TO FRONT CH
6CH INPUT
SUB_WOOFER
Config2
-28dBFS
10dB
-18dB
PRE AMP
5
AVR-2105/885 / AVC-1890
FRONT VS SW
+
A/D
A/D
DIR
+--
6CH IN
(200mV)
DIGITAL
CD IN
6CH IN
-12dB
A/D IN
REV AMP
A/D IN
REV AMP
A/D IN
REV AMP
HPF
D/A OUT
LPF
-31.2dB
MUTE
REV AMP
SUM S/W
SW SUM
REV AMP
-11.66dB
ELECTRIC
VOLUME
21.56dB up
PRE AMP
-13.14dB
MUTE
POWER AMP
-35.5dB down
-20dB
-10dB
0dB
10dB
20dB
30dB
40dB
6CH IN
CD IN
+
INPUT
BUFFER
AMP
---
0dBFS
DSP with
Tone control
-38dBFS
-30dBFS
SW
-20dBFS
-10dBFS
Front
0dBFS
D/A
-13.2dB
--
1.54dB up
-16.7dB
18dB down
+
ATT
-20dBFS
18dB down
16.6dB up
-13.06dB
26.02 dB up
-30dBFS
-10dBFS
FRONT
6.8dB up
Config1
6.8dB up
D/A
-34.7dB
-29.66dB
14.5dB up
H/P OUT
73mV
SPK OUT
FRONT
4.35V
H/P OUT
SPK OUT
FRONT
FRONT VS SW
D/A OUT
100mV REF