Pioneer XV-DV515 Service Manual page 115

1
Protection circuit that activates against a DVD PRTECT error
6 The DVDM monitors the voltage of the main power supply by VDET signals.
In Normal mode, the VDET signal is at the MID level (3.3 V). In the following conditions, the VDET signal level becomes L or H, and
the microcomputer is notified of this abnormality.
V+12 V+5 V+12
R927
47k
R925
R929
R928
0
10k
4.7k
Q924
R930
10k
D924
V+12
V+6 V+5
R933
15k
D926
R934
10k
D927
D925
Items to be detected by VDET
(1) When the power voltages inside the DVDM become abnormal, as shown in the table below
Status
In Normal mode
When an abnormality is generat
(2) When the VDET signal to the microcomputer is interrupted because of defective soldering of the 30-pin connector or incomplete
insertion of FFC
→ The VDET level is lowered by the pull-down resistor (1 Mohms) on the side of the microcomputer.
1
2
VPR+8
R923
47k
V+12
Q921
Q923
R924
10k
Q922
D923
R922
470
Q925
Q926
UDZS4.7B
R931
47k
Power Voltage
Q923
off
<1V (on)
VDVD+12
>15.5V off
−
<5.2V
VPR+8
−
>12.6V
−
V+6 <3V
−
<3.6V
V+5
−
>6.6V
−
<2.5V
V+3R3
−
>4.25V
2
3
B F
DVDM Assy
D922
Through
TRADE2
POWER
V+3R3
R921
470
20
8
D921 C921
0.1
Operation
Q924 Q922 Q921 D921
off off off off
(on) (on) (off) off
off off off off
off off off off
on on on on
− − − −
off off off off
on on on on
− − − −
− − −
(on)
XV-DV515
3
4
CONTROL Assy
R5588
220
VDET
µcom
17
R5591
1M
C5580
IC5501
0.01
PDC104A
VDET voltage
D922 Q926 Q925
off off off Mid
on off off
off on on
−
on on
−
off off
−
on on
−
on on
−
off off
− − −
− − −
4
A
B
C
L
L
L
H
L
L
D
H
L
H
E
F
115