Pioneer SC-LX90 Service Manual page 101

1
A
If you come to this section because the power amp block is diagnosed as being in failure:
If only sound of a specific function or in a specific audio mode is not output, the defective block is not the ICEPOWER
block. The ICEPOWER block is diagnosed as being in failure only when sound of all functions is not output.
1 Set the speaker setting for all channels to Large.
2 Set ALL CH to Bi AMP.
3 Set the function to Multi Ch In.
4 Set the listening mode to Pure Direct (PCM Direct).
5 Fix the signal switch at Analog.
B
Is the oscillation waveform (sine wave with about 450 kHz frequency, 1.5 to 2.0 Vrms)
output from the speakers when no signal is input?
Is the signal input to the AMP?
C
OK
Is muting canceled?
NG
D
Check the
OK
cables and
power supply.
Failure in the
ICE POWER AMP Assy
E
* How to confirm that 5-V/12-V power for the ICE is properly
supplied:
Check the ICE REG Assy.
Check the power supply to the ICE POWER AMP Assy.
Check OP-AMP power supply to the ICE INPUT 4CH Assy
and the ICE INPUT 6CH Assy.
* How to confirm that a signal is input to the ICE AMP block:
Check the cables.
Check the output from the ICE INPUT 4CH Assy and the
ICE INPUT 6CH Assy.
F
* How to confirm that the speaker relay is activated:
Check if sound of relay operation is heard when the SP
Relay ON/OFF key on the front panel is pressed.
46
1
2
Diagnosis of the ICEPOWER Block
OK
NG
Is ± 12-V power
supplied?
NG
Check the
OK
cables and
power supply.
2
3
Is the speaker relay ON?
OK
Is ± 5-V power supplied?
OK
Failure in the ICE
POWER AMP Assy
Is 24-V power supplied to the +24V_
Relay_Drive?
OK
Is the +24V_Relay_Drive
controllable?
OK
Failure in the
ICE POWER
SMPS Assy
SC-09TX
3
4
NG
NG
NG
Check the
cables and
power supply.
NG
Failure in the
ICE POWER
SMPS Assy
NG
Check the
cables and
power supply.
4