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4. DIGITAL AMP UNIT
4.1. MAIN PWB
No sound from the speakers.
Protector operates.
After the power is turned on, is the power supply to each AMP
IC normally supplied?
CP110(6)-(11)pin :
+29V
CN405(6)pin :
+12V
After the power is turned on, is the RESET signal to the AMP IC
released?
IC109(2)pin "RSET"
0V :
RESET ON
3.3V :
RESET release
(When the protector operates, measure the output while power
is turned off.)
After the power is turned on, check whether 3.3V is output from
the SD output of the AMP IC (15) pin.
(When the protector operates, measure the output while power
is turned off.)
Check that DC_PROTECT of the SP output is not DC detection.
Q133 collector
0V :
DC detection
3.3V :
Non DC detection (normal operation)
(When the protector operates, measure the output while power
is turned off.)
Check whether SP output RELAY(RL100) is normal.
When SP output RELAY is normal, check it whether input Buffer
OPAMP (IC110/111) of each IC is normal.
YES
YES
YES
YES
NO
Check the SMPS PWB
NO
Check the IC102(46)pin output of MAIN PWB.
NO
AMP IC is not operating.
Replace the AMP IC.
NO
Check SP output +/- of each IC at a stage before
RELAY(Lead(Hot side) of C184, C201, C228, C249).
Replace the IC that about 14.5V DC is not output.
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