Yamaha P-105B - Page 62

P-35B
The DM Circuit Board is provided with test points for service check purposes.
Check the test points on the DM Circuit Board if the following symptoms appear.
Symptoms and check items
1. No light with Power SW ON
--
> Check items
②
to
④
sequentially
2. No sound or distorted sound
--
> Check items
①
,
⑥
and
⑦
, and OUTPUT check items.
OUTPUT
Note: Use the standard AC adapter PA-150A or PA-150U for check operation.
Note: “O” mark expresses normalcy and “X” mark expresses a failed state.
DM Circuit Board (WZ912400)
TEST POINT
NO. SPEAKER OUTPUT
PHONES/
OUTPUT
DAC-L/R
TEST POINT
Parts with Possible Defects
1 X X X IC100
2 O X X IC301
3 X O O IC302 or HP JACK
4 O X O IC303
NO. Test Point Circuit Judgment Criteria Measured by Parts with Possible Defects
①
+12V Power supply for More than 10.0V Multimeter TR502
DM Circuit Board (On JK Circuit Board)
②
+HP Power supply for More than 10.9V Multimeter TR102
Headphone Circuit
③
+3.3D 3.3V power for 3.3V ±0.3V Multimeter IC101
digital circuit
④
+1.8D 1.8V power for 1.8V ±0.1V Multimeter IC102
digital circuit
⑤
/RESET CPU and Memory 3.3V ±0.3V Multimeter IC106
reset signal
⑥
DAC-L DAC output
There shall be audio output Signal checker IC301 or IC100
L channel
without distortion
⑦
DAC-R DAC output There shall be audio output Signal checker IC301 or IC100
R channel
without distortion
①②
⑥
⑦
④
③
⑤
P-105B/P-105WH/P-35B/L-85WH/LP-5AWH
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