Trouble Shooting - Pioneer XV-EV61 Service Manual

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7.1.4 TROUBLE SHOOTING

Microcomputer Section (IF/AF Assy : IC5501)
A
Symptom
• The unit cannot be turned on.
The unit shuts itself off soon after it is
turned on.
B
• DVD does not operate at all.
• Time is not displayed in FL display
during DVD function.
All operation keys are disabled.
C
D
E
F
122
1
2
Possible Cause
The microcomputer was not reset.
The AC pulse is not input.
The oscillation circuit of the microcomputer
does not function.
• If the Function is DVD, the voltage of the
VDET input (Pin 17) is either 0.5
less or 0.85 Vdd* or more.
• The voltage of the PROTECT input
(Pin 22) is 0.71 Vdd* or less.
Communication with the DVD
microcomputer has not been established.
The unit recognizes that an operation key
has already been pressed.
XV-EV61
2
3
Check Method
Check if the level of the terminal XRESET (Pin 8) is "H."
If it is not, check the RESET circuit.
Check if the AC pulse is input to Pin 4 of the AC input
terminal. If it is not, check the AC pulse generation circuit.
The microcomputer or the oscillation circuit is broken.
Change the microcomputer or the oscillation circuit.
Vdd* or
If the voltage at Pin 17 of the VDET terminal of the
microcomputer is either 0.5 Vdd or less or 0.85 Vdd or
more, adjust so that it stays between 0.5 and 0.85 Vdd.
• Check that the terminal (Pins 23-25, 29, and 30) for
communication with the DVD microcomputer is live,
and if it is not, check if the flexible cable is
disconnected.
• Check if an "H" signal is output to Pin 93 of the
XDVDRST terminal.
If no operation key has been pressed, check if the
voltage at Pins 18 of the KEY input terminal is 5 V. If it is
not, check if the operation switch on the line is in failure.
* Vdd= Approx. 5V (depending on the unit)
ex.) 0.85Vdd= 0.85 × 5 (V)
3
4
= 4.25 (V)
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