Yamaha IPA8200, Service Manual

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D972
C980
1
220 ohms/10W
REAR
FRONT
■
SERVICE PRECAUTIONS （サービス時の注意）
Safety measures
• Some component parts on the INPUT POWER circuit
board and POWER circuit boards maintain a high
voltage even when the power is switched off.
For this reason to avoid an electrical shock, do not touch
the upper metallic part of the following capacitors until
the remaining voltage has discharged.
[Discharging Method]
Before starting the service work, connect discharging
resistors (220 ohms 10W) to the terminals indicated in
the figure below to discharge electricity. (13 points)
The required discharging time is about 10 seconds per
each. Check that the DC voltage between the terminals
measures close to 0 (zero) volts using a multi-meter to
make sure that the discharge is completed.
安全対策
・ INPUT POWER シート、POWER シートの部品の一部
には電源 OFF 状態でも高電圧が残ります。
感電防止のため、残った電圧を放電するまで下記のコ
ンデンサの上部の金属部分に触らないでください。
［放電方法］
修理作業を始める前に、放電抵抗（220 Ω、10 W）を
下図に示す放電用の端子間に接続します。（13 箇所）
放電に必要な時間は各々約 10 秒です。放電完了確認の
ため、端子間電圧がほぼ０（ゼロ）Ｖであることをテ
スターでチェックします。
INPUT POWER cricuit board
INPUT POWER circuit board
Capacitors /
コンデンサ
Discharging point /
放電箇所
C980 ① D972: + pin <==> D972: - pin
POWER circuit board x 4
Capacitors /
コンデンサ
Discharging point /
放電箇所
C912, C913 ② D904: cathode <==> D901: - pin
C914 ③ Between both terminals of R922
C915 ④ Between both terminals of R923
IPA8200
8