– 5 –
In such a case, check also if the POWER AMPLIFIER circuit or power supply circuit has any abnormalities or not.
2-2. Regarding reset
There are cases that the machine does not work correctly because the MICROCOMPUTER is not reset even though the AC power
cord is re-inserted, or the software reset (pressing the STOP key + POWER key) is performed.
When the above described phenomenon occurs, it can lead to wrong judgement as if the MICROCOMPUTER is defective and to
exchange the MICROCOMPUTER. In such a case, perform the forced-reset by the following procedure and check good or no
good of the MICROCOMPUTER.
1
1
1
1
1
Remove the AC power cord.
2
2
2
2
2
Short both ends of the electrolytic capacitor C113 that is connected to VDD of the MICROCOMPUTER with tweezers.
3
3
3
3
3
Connect the AC power cord again. If the MICROCOMPUTER returns to the normal operation, the MICROCOMPUTER is
good.
Note:
The reference number or MICROCOMPUTER pin number of transistor (Q110) and electrolytic capacitor (C113) can change depending
on the models. Be sure to check the reference numbers on schematic diagram before starting the discharging work.
2-3. Confirmation of soldering state of MICROCOMPUTER
Check the soldering state of the MICROCOMPUTER in addition to the above described procedures. Be sure to exchange the
MICROCOMPUTER after surely confirming that the trouble is not caused by poor soldering but the MICROCOMPUTER itself.
Fig-2-2
MICRO-
COMPUTER
MICR
OCOMPUTER
FRONT C.B
FRONT C.B
VSS
VDD
C113
*
%
C113
18
15
Short with tweezers.
Содержание XR-HG5MD
Страница 14: ...SCHEMATIC DIAGRAM 1 MAIN 1 2 AMP SECTION 14 ...
Страница 15: ...SCHEMATIC DIAGRAM 2 MAIN 2 2 TUNER SECTION 15 ...
Страница 18: ...SCHEMATIC DIAGRAM 3 FRONT 18 ...
Страница 20: ...SCHEMATIC DIAGRAM 4 PT 20 ...
Страница 24: ... 24 IC BLOCK DIAGRAM IC LC72131D IC M61500FP ...
Страница 25: ... 25 IC BU2092F IC BA3835F ...
Страница 26: ... 26 IC LA1837NL IC BU2099FV ...
Страница 27: ... 27 IC BU1920FS ...
Страница 28: ... 28 FL HNA 13MM14T GRID ASSIGNMENT ANODE CONNECTION GRIDASSIGNMENT ...
Страница 29: ... 29 ANODECONNECTION ...
Страница 40: ...2 11 IKENOHATA 1 CHOME TAITO KU TOKYO 110 JAPAN TEL 03 3827 3111 Printed in Singapore 9420208 0251431 ...