Trouble Shooting - Pioneer XR-A9800D Service Manual

XR-A9800D

7.1.2 TROUBLE SHOOTING

XR-A9800D microcomputer troubleshooting
Symptom of problem
• The power supply does not enter
though the power supply outlet is
put, standby LED lit even if the
POWER key is pushed.
• It enters the state of POWER OFF
soon even in case of the POWER
ON.
• DVD does not operate at all.
• Time is not displayed in FL DISPLAY
at the DVD function.
• KEY is not accepted at all.
• The Spectrum analyzer display does
not displayed.
84
Thought cause
• The microcomputer is not reset.
• The AC pulse is not input.
• The oscillation circuit of the microcomputer
does not oscillate.
• The PROTECT input does not become "H".
• If the function is DVD, the 3.3DETECT input
is 2.9V or less.
• It does not communicate with the DVD
microcomputer.
• It is recognized that other KEY has already
been pushed.
• The Spectrum analyzer input is not input.
Check method
• Whether terminal RESET (11Pin) is "H" is confirmed.
The operation of the RESET circuit is confirmed if
not becoming "H".
• Whether the AC pulse is input to AC input terminal
(26Pin) is confirmed. If the AC pulse is not input,
the AC pulse generation circuit is confirmed.
• The microcomputer or the oscillation circuit is broken.
The microcomputer or the oscillation circuit is
exchanged.
• Whether "H" is input to PROTECT input (55Pin) when
"H" is output to the terminal of SCAN ON is
confirmed. If "H" is not input, diode D5570 etc. are
confirmed.
• If the voltage of the 3.3DETECT (24Pin) terminal of
the microcomputer is 2.9V or less, the voltage is
adjusted to 2.9V or more.
• Whether terminal (5,27Pin,95-97Pin) for the
communication with the DVD microcomputer does
the communication operation is confirmed. If the
communication operation is not done, whether the
FFC cable etc. are disconnected is confirmed.
• Whether "H" is output to terminal DVDRESET (3Pin)
is confirmed.
• When KEY is not pushed, whether KEY input
terminal (18-20Pin) is 5V is confirmed. If the KEY
input terminal is not 5V, whether KEY SW on the
line breaks is confirmed.
• Whether Spectrum analyzer input terminal (23Pin)
is 0.3V or more is confirmed. Whether DISPLAY
MODE is DISP6 when it is 0.3V or more is confirmed.
Whether Spectrum analyzer IC control terminal (8-
10Pin) was changeable when it is 0.3V or less is
confirmed. If it was changeable, whether Spectrum
analyzer IC breaks is confirmed.