Panasonic SAXR55 - A/V RECEIVER, Service Manual

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LCD display Symptom Cause and Remedy
OVERLOAD Speaker short, amplifier failure Speaker short and failure in
power amplifier, pre-amplifier
circuits. Check for faulty parts
and replace with new parts if
necessary.
Humidity protection activated
F70 Communication error between
sub micro- processor and its
peripheral LSI Failure sub-micro processor
and its peripherals LSI. Check
for faulty parts and replace with
new parts if necessary.
F76 When the power is turned on,
the unit power automatically
turns off; the power cannot be
turned on. Failure in the power circuit
system of the unit. This may
happen when the direct current
electricity is supplied to
speaker terminals. Check for
the above and replace with new
parts if necessary.
9.3. Returning to Normal Display
Press the POWER button on the unit to exit the function. The power is turned off.
9.4. Overload/Shutdown Detection intenal Condition
It detects OVERLOAD, POWER MALFUNCTION with [THRM_DET], [SHORT_DET] and [DC_DET]
input port. It detects the following condition depending on the input of the port as below table.
(H: DC ± 5V / L: DC ± 0V)
PROT Detection of malfunction Display and operation
SHORT_DET THRM_DET
DC_DET
H L H Normal -----
L L H Speaker Short, Malfunction of
Amplifier
[OVERLOAD] / POWER
L H H Detection of THERMAL
PROTECTION
- - L Detection of POWER
MALFUNCTION
[ _ _ _ F76 _ _ _ ] / POWER
OFF
9.5. Overload/Thermal Detection Display
When overload is detected, automatic POWER OFF will occur. But if any key on the remote
control other than the [POWER] key is pressed before that (including the [HELP] key), the scroll
display will show [SWITCH_OFF_POWER]. Then, 1 second after display of message,
[OVERLOAD] will be shown on the scroll display.
9.6. Activating Self Diagnosis Function (Servicing Mode)
This mode can be used during servicing.
1. Plug the AC adapter to the power source. Press and hold down
the [MULTI CONTROL] button and the [SPEAKERS A] button, and