Pioneer VSX-1018AH-K Service Manual page 57

5
[6] USB/iPod Troubleshooting
Step 1: Check of power supply
* Turn ON the power of product and check the power supply by
USB iPod function.
CN704 (Pins 8,9) 5V input (for DSP&USB)
1
Is
No
the voltage
5 V ?
Yes
Connect the CN704.
2
CN704 (Pin 10)
5V input (for USB bus power)
Is
No
the voltage
5 V ?
Yes
Connect the CN704.
3
IC705 (Pin 5)
3.3V regulator output (V3D)
Is
No
the voltage
3.3 V ?
Yes
The output and GND maybe
short-circuited.
Check the peripheral circuit.
4
Q871 (collector)
Local power supply for 3.3V USB (V+3DU)
Is
No
the voltage
3.3 V ?
Yes
Check the peripheral circuit of Q871
and Q872.
Replace of Q871 and Q872.
5
IC801 (Pins 19,39) USB u-COM (V3US)
Is
No
the voltage
3.3 V ?
Yes
5
6
In sent the
Yes
CN704 connector
securely
?
Check the voltage
No
on CN103 side of
MAIN Assy.
In sent the
Yes
CN704 connector
securely
?
Check the voltage
No
on CN103 side of
MAIN Assy.
Is IC705
No
abnormally hot
?
Replace of
Yes
IC705.
No
Is base (USB PWR)
of Q872 high?
Check the
Yes
voltage Pin 7
(USB POWER)
of CN701
(CN702) at 5V.
Check the pattern between
Q871 and IC801.
6
7
6
IC808 (Pins 1,40)
Is
the voltage
3.3 V ?
Yes
7
IC851 (Pin 16)
Is
the voltage
3.3 V ?
Yes
8
IC802 (Pin 1)
Is
the voltage
5 V ?
Yes
Power supply is OK
To step 2
VSX-LX51
7
8
iPod activation IC (V3UI)
No Check the pattern between
Q871 and IC808.
Logic IC (V3UL)
No Check the pattern between
Q871 and IC851.
USB bus power (V5USB)
Is Pin 4
No
No
(USBCTRL) of IC802
high?
Check the
Yes
voltage Pin 4
(USB CTL)
of CN701
(CN702) at 5V.
Check the peripheral circuit of
IC802, and is not XFALG LOW?
Replace of IC802.
8
A
B
C
D
E
F
57