Pioneer SC-99 Service Manual page 29

5
DAC HIGH ASSY DIGNOSIS

No sound from speakers and Preout in EXT STEREO
No sound in plural channels
Yes
Check of power source: Is there ±12V in CN2004 ?
Yes
Check of power source: Is there ±6V in CN2004 ?
Yes
The signal(DABCK, DALRCK, each DATA) of the relevant
channel exist in CN2001.
Yes
80MHz clock exist in 19pins of IC2009 and IC2010.
Yes
Check the broken point (start with checking the relevant
channel of CN2003), and check the peripheral circuit.

No sound only in COAX input or OPT input
Check the peripheral circuit of IC2003.

No sound only in analog input
Check the peripheral circuit of IC2027.

No sound only from ZONE 2 of FRONT USB
Check the peripheral circuit of IC2026.

No sound only in BT
Check the 14, 16pin of JA2010, the power source and control signals.
5
6
No
SC-99
6
7
Check the broken point (start with checking the
relevant channel of CN2003)
No
Check the circuit of the connection destination.
No
Check the circuit of the connection destination.
No
Check the circuit of the connection destination.
No
Check the peripheral circuit of X2001.
7
8
A
B
C
D
E
F
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