Dc Offset Error - Kenwood DPX502 Service Manual

DPX502/502U/502UY
DPX-MP5100U
● Purpose
Prevent customer's vehicle speakers damages, burnouts,
and smoking.
Avoid the connected speakers to be bur ned out,
damaged, or to smoke when DC occurs between the
audio power amp. + and - outputs.
● Processing after detection
• System status
• At the detection of DC error, error data is to be saved
immediately (E2PROM error log save area).
• Display the error message on the display. The system
shall maintain the current condition, including the
operation. Shut down audio system power supply. Set
Mute to ON.
• Although switching between Power OFF and ON (ACC,
BU, and Key operation) is valid, switching from Off to ON
shall be error until the µ-com is reset.
∗ While power-on, even if the IC2VI DCErr output terminal
logic recovered to normal level value, the error condition
shall continue.
• Prohibit to save the backup/installer memory to E2PROM
(nonvolatile memory).
• Controlling µ-com terminal
• Set Mute for all channels including for pre-out.
• Turn off power IC control system power supply. (Set AMP-
Standby function to valid)
• Set P-Con output to OFF (Logic by which external AMP
unit is turned off).
∗ The purpose is to shut down audio output. Basically, the
logic sets the audio output system signal line when in
Standby source.
PWIC_STBY
PWIC_MUTE
AUD_MUTE
14

DC OFFSET ERROR

2.0sec or more 1.5sec or more
1.0s
Improper connection Capacitor leak
detection period detection period
• Key specifi cation
• Other keys than eject and power keys are invalid.
• Display specifi cation
• Display the "PROTECT" string and blink all characters at
1Hz.
∗ Use the indication below with the highest priority (error
message), and maintain the error message even when
the source is changed.
Display example
alternately
PROTECT
● Cancel Condition
• Press the Reset terminal on the main body. Or set Backup
to OFF (Unplug and plug back in the DC connector).
The history is maintained (E2PROM data is saved).
• If DC error is detected during the capacitor leak detection
period, the clearing the error by the reset is limited to 4
times.
The startup is inhibited for the 5th time and later reset.
("PROTECT" display has to be blinked.)
● Note while in the test mode
• While in the test mode, even if DC leak is detected, it is
not written into E2PROM.
When an error is detected, the display is enabled.
● Other
• Function for checking and clearing data in E2PROM by a
given key shall be included. (Used at production dpt. and
service center, etc.)
0.5s or more
1.0s
AUD_MUTE
(independent H→L→H)
Other (improper detection etc.)
detection period
Blink
at 1Hz
50ms
or more