Onkyo ED901 Service Manual

ONKYO USA CORPORATION

10/01/1999

Model: ED901

Classification:

PROBLEM:

SOLUTION:

FIG 1

Buzzing sound in rear channel when AC3 software is played.

Noise is reproduced in all channels after having the unit playing for a long time.
AC3 light flickers (mute) and sound tends t o distort.

The noise is normally
associated with metallic heat
sink Q903 and Q905 type
regulators used in early
production. To avoid this
problem, cut jumper J192.
Replace C922 to 1000pf 50V
(103Z) ceramic capacitor.

FIG 3

Service Tip

(on older version units)

Add a jumper across landings located
near C854 seen on the left, to reduce
the ground impedance.

Q701 should be replaced with current version
IC. Part # 22240971 version 0971 Y15A. If
the Microprocessor is any older, it is likely the
above two service tips should be
accomplished as well.

Cut foil pattern at this (X) point as
well. It is located solder side of
C918.

FIG 2

FIG 4