Denon S-5BD, Service Manual

Page: 43 / 207

43
4. DIGITAL AMP UNIT
4.1. 8U-210080-1
No sound from the speakers.
Protector operates.
After the power is turned on, is the power supply to each AMP
IC normally supplied?
CY044(1),(2)pin : +47V
CX211(13),(14)pin : +12V
After the power is turned on, is the RESET signal to each AMP
IC released?
CX211(9)pin "AMP_RESET"
0V : RESET ON
3.3V : RESET release
(When the protector operates, measure the output while power
is turned off.)
Is Clock output from IC102?
Check that Clock of about 4MHz is output from IC102(13),(14)
pin.
(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 each AMP IC (15) pin. (Measure it on the
cathode side of the connected diode.)
(When the protector operates, measure the output while power
is turned off.)
Check that DC_PROTECT of the SP output is not DC detection.
TR301 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(RL401/402/403/404/405) is
normal.
When SP output RELAY is normal, check it whether input Buffer
OPAMP (IC104/105/106/107/302) of each IC is normal.
Check the source of the power supply.
(8U-210078 SMPS UNIT)
Check the IC301(6)pin output of Main Unit(8U-21079).
IC102 is not operating.
(All channels do not operate.)
Replace the IC102.
AMP IC is not operating.
Replace the AMP IC.
Check SP /- of each IC at a stage before
RELAY(Lead(Hot side) of C251-C258, C341, and C342).
Replace the IC that about 24V DC is not output.
NO
NO
NO
NO
NO
YES
YES
YES
YES
YES