Amp Block Trouble Shooting - Pioneer S-W1EX Service Manual

1

7.3 AMP BLOCK TROUBLE SHOOTING

The repair flow of the AMP section
A
PowerON
After 4 seconds
A signal from CN481.
(Sound from the speakers)
no output
The LED lights.
yes
B
The speaker relay
is on.
yes
Control Assy
Input, D AMP Assy
yes
Replace the hot IC, since it is no
C
longer serviceable.
'+''-' of multi-meter is reverse.
Check the resistance between G and S of the FETs (Q421, 431, 441, and 451) with the multimeter.
"+" is assigned to G and "-" is assigned to S for the multimeter.
A
Multi-meter : ADVANTEST TR6847 or equivalent
FET : IRFB23N15D
D
30kΩ to 40kΩ
All FETs are O.K.
Check soldering at IR2011S
(IC421, IC441)
E
Accidental
failure mode
F
44
1
2
output
Go to
no
SMPS part
no
A
The 8-pin IC is no
Solder shorting?
hot.
Solder correction
2
Everything is all right, except for the waveform
(resistance of R471 and 472 is 10 ohms or more).
Everything is all right, except for the relay
not being turned on.
Although the VOL is minimum, there is
output from CN481.
2
3
Level is low.
Level is low. Waveform is not normal.
yes
Check the screws
CrossOver 50Hz?
of D AMP ASSY.
Turn to Bypass and try again.
no
SMPS Assy Voltage of IC32?
yes
Cases other than 2–4 below.
1
3
1k to 10k
All FETs are O.K.
Replace IR2011S
(IC421, IC441)
Replace R471 and R472 with new ones.
Replace Q506 and Q507 with new ones.
Solder shorting of VR3141 of the
CONTROL Assy.
S-W1EX
3
4
Check soldering of
OK
IC421,441(B-2)
Less than [ 10V ]
Replace IC32.
0 to 1k
FET has been broken.
Replace IR2011S located on
the same side as the FET
with low resistance.
4
Check other
symptoms.
4