Trouble Shooting; Power - Denon AVR-E300 Service Manual

TROUBLE SHOOTING

1. POWER

1.1. Power not turn on
Power not turn on.
When the power turned on,
does the X indicator on the
front panel flashing green?
YES
About 10 seconds later,
does the X indicator on
the front panel turn lighting
green ?
NO
Is the fuse blown?
NO
Check voltage of CN771 (4-
7PIN) of DIGITAL B'D while
the X indicator is flashing
green.
4,6,7 PIN : 3.3V
5 PIN : 0V
Pull out connector (BN502) of
MAIN BD, and check "2. Errors
checking mode".
(Refer to 23 page.)
1.2. Fuse is blown
Check for leaks or short
circuits in the primary side
parts, and replace any
defective parts.
When the power turned on,
NO
does the X
indicator on the front panel
flashing red?
NO
Is the fuse blown?
NO
Is a DC 5V voltage being
supplied from the SMPS
B'D (BN601) to the DIGITAL
B'D?
YES
Check µ-com periphery
circuitry of DIGITAL B'D and
replace any defective parts.
YES
YES
Refer to 1.2. Fuse is blown.
4,6,7 PIN : 0V
Check circuitry and parts from CN751
5 PIN : 3.3V
on the DIGITAL B'D to the µ-com for
damage and shortcircuits, and replace
any defective parts.
Fuse is blown
Check for short circuits in the
rectifier diodes and circuitry of
the secondary side rectifying
circuits, and replace any
defective parts.
After repairing, also replace the fuse.
YES
YES
Refer to 1.2.Fuse is blown.
Is a DC 5V voltage output
NO
when the cord supplying the
power from the SMPS B'D
to the DIGITAL B'D (CN751)
is unplugged?
YES
Check circuitry and parts from
CN751 on the DIGITAL B'D
to the µ-com power supply for
damage and shortcircuits, and
replace any defective parts.
Are there any incomplete
connections in the connectors
connecting between the
various circuit boards?
YES
Connect the connectors properly.
Check for short circuits in
the power stabilizer unit's
regulator output terminal and
the ground, and replace any
defective parts.
67
To troubleshooting 6.
NO SMPS.
(Refer to 76
page.)
Check "2. Errors
NO
checking mode".
(Refer to 23
page.)