Psr-S970.Dmh.circuit.board.check.method - Yamaha PSR-S770 Service Manual

■ ■ PSR-S970■DMH■CIRCUIT■BOARD■CHECK■METHOD
The DMH Circuit Board is provided with test points for service check purposes.
Check the test points on the DMH Circuit Board if the following symptoms appear.
Symptoms and check items
(1) No LCD display with Power SW ON --> Check items ① to ⑦ sequentially.
(2) No sound or distorted sound --> Check items ① , ⑧ to ⑬ sequentially and OUTPUT check items.
Test■Point
NO. Test Point
① PV
② 16V
③ +5D 5V power for digital circuit
④ +3.3D 3.3V power for digital circuit
⑤ +1.3D
⑥ +1.0D
⑦ RESET CPU & memory reset signal
⑧ 12A 12V power for analog circuit
⑨ 5A 5V power for analog circuit
⑩ OUTL
⑪ OUTR
⑫ HPL
⑬ HPR
Note1: Use the standard AC adapter PA-300C for check operation.
Output■states
NO. Tweeter Woofer
1 × ×
2 × ×
3 ○ ×
4
× ○
5 ○ ○
6 ○ ○
7 ○ ○
Note: " ○ " mark expresses normalcy and " × " mark expresses a failed state.
Circuit
Power supply
for Power amplifier IC
Power supply
for digital circuit
1.3V power for CPU
1.0V power for TG
AUX output L channel
AUX output R channel
HP output L channel
HP output R channel
PHONES OUTPUT
×
○
○
○
×
×
○
Judgment criteria
More than 14.0V
More than 14.0V
5.0V±0.5V
3.3V±0.3V
1.3V±0.1V
1.0V±0.1V
3.3V±0.3V
12V±1V
5.0V±0.5V
There shall be audio output
without distortion.
There shall be audio output
without distortion.
There shall be audio output
without distortion.
There shall be audio output
without distortion.
Parts with possible defects
IC001, IC002, IC007 or Error Detect
×
Circuit
○ IC001, SP-/MUTE Signal or HP JACK
○ IC802
IC806
○
× IC807 or IC805
IC800, TR800 or
○
RY200 (On HP circuit board)
IC801 or
×
TR103-TR106 (On AJACK circuit board)
PSR-S770/PSR-S970
Measured by Parts with possible defects
TH100 or FT100
Multimeter
(On AJACK circuit board)
TH100 or FT100
Multimeter
(On AJACK circuit board)
Multimeter IC810
Multimeter IC810
Multimeter IC209
Multimeter IC606
Multimeter IC004
IC100
Multimeter
(On AJACK circuit board)
Multimeter IC811
Signal Checker IC801 or IC807
Signal Checker IC801 or IC807
Signal Checker IC800 or IC807
Signal Checker IC800 or IC807
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