– 6 –
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.
Summary of Contents for XH-A1000
Page 19: ... 19 SCHEMATIC DIAGRAM 1 MAIN 1 4 AMP SECTION CONNECT 1 3 ...
Page 20: ... 20 SCHEMATIC DIAGRAM 2 MAIN 2 4 POWER SUPPLY SECTION ...
Page 21: ... 21 SCHEMATIC DIAGRAM 3 MAIN 3 4 DECK SECTION ...
Page 22: ... 22 SCHEMATIC DIAGRAM 4 MAIN 4 4 PRO LOGIC SECTION ...
Page 23: ... 23 SCHEMATIC DIAGRAM 5 FAN ...
Page 25: ... 25 SCHEMATIC DIAGRAM 6 FRONT CONNECT 2 3 DECK DECK MOTOR ...
Page 27: ... 27 SCHEMATIC DIAGRAM 7 OPERATE KEY MIC LED A D ...
Page 29: ... 29 SCHEMATIC DIAGRAM 8 LOW AMP ...
Page 31: ... 31 SCHEMATIC DIAGRAM 9 5CH AMP ...
Page 33: ... 33 SCHEMATIC DIAGRAM 10 VIDEO I O VIDEO JACK VIDEO 3 CONNECT 3 3 ...
Page 34: ... 34 SCHEMATIC DIAGRAM 11 SCART ...
Page 36: ... 36 SCHEMATIC DIAGRAM 12 TUNER ...
Page 38: ... 38 SCHEMATIC DIAGRAM 13 PT ...
Page 40: ... 40 FL BJ733GK GRID ASSIGINMENT ANODE CONNECTION PIN CONNECTION ...
Page 41: ... 41 FL BJ734GK GRID ASSIGINMENT ANODE CONNECTION PIN CONNECTION ...
Page 42: ...IC BLOCK DIAGRAM 42 ...
Page 43: ... 43 ...
