Pioneer PDP-4280HD, Service Manual

Page: 61 / 176

PDP-4280HD
61
5 6 7 8
5 6
7
8
C
D
F
A
B
E
No
No Yes
Has the sound been emitted from
the Headphones?
Is sound muting set?
Is the volume set to 0?
No
Check the communications around the IC8871 and between the IC8871
and the microcomputer. If there was no ploblem, replace BH3544F.
Cancel muting, then check again.
Yes
Raise the volume, then check again.
Is a signal output from IC9101?
(pins 38, 39)
No
Yes
No
Check around the IC9101 and repair the failure points.
Is a signal output from IC8871?
(pins 1, 7)
Yes
Replace the cables or SIDE IO Assy.
NG
Check the cables between CN8801
and CN9351 or check around the
Headphones jack.
B
42 43
47 48
Waveforms
Input signal: L/R 1 kHz, 0.5 Vrms (VOL 30)
44
49
45
50
46
51
52
53
CN9251 - pins 2, 4
V: 2 V/div H: 1 mS/div
IC9101 - pins 54, 55
V: 2 V/div H: 5
μ
S/div
CN9251 - pins 5, 7
V: 2 V/div H: 1 mS/div
IC9101 - pins 24, 25
V: 2 V/div H: 1 mS/div
52 53 IC9101 - pins 38, 39
V: 1 V/div H: 1 mS/div IC8871 - pins 1, 7
V: 1 V/div H: 1 mS/div
IC9201 - pins 34, 38
V: 10 V/div H: 5
μ
S/div
IC9151 - pins 2, 3
V: 2 V/div H: 1 mS/div
IC9201 - pins 44, 52
V: 10 V/div H: 5
μ
S/div
IC9151 - pins 5, 6
V: 2 V/div H: 1 mS/div
IC9101 - pins 52, 53
V: 2 V/div H: 5
μ
S/div
IC9151 - pin 1, etc.
V: 2 V/div H: 1 mS/div