Performance Graphs; Troubleshooting - Yamaha P4500 Owner's Manual

Performance Graphs

P4500
5k
1k
100
20
1
P1600
5k
1k
100
20
1

Troubleshooting

The following table lists the main causes of abnormal operation and the corrective measures required, as well as the protective
circuit operation in each case.
Indicator
CLIP indicator lights.
TEMP indicator lights.
PROTECTION indicator
lights.
10
Mode:STEREO
Both ch Driven
RL=4Ω, f=1kHz
10 100
Output Power [W]
Mode:STEREO
Both ch Driven
RL=4Ω, f=1kHz
10 100
Output Power [W]
Probable Cause
There is a short at a speaker
terminal, amplifier terminal,
or wire.
The amplifier load is exces-
sive.
The heat sink temperature
has exceed 85˚C.
The heat sink temperature
has exceeded 95˚C.
A DC voltage of +/–2 V or
greater was generated in the
power amplifier's output
circuit.
P3200
5k
1k
100
20
1k 1
1k
Remedy
Locate and correct the cause
of the short.
Use a speaker system with
an impedance of at least 4Ω
(stereo) or 8Ω (bridge).
Check the ventilation slots,
and improve the airflow
around the amplifier.
Check the amplifier ventila-
tion conditions and take
appropriate measures to
improve airflow around the
amplifier.
Consult your dealer or
nearest Yamaha service
center.
Mode:STEREO
Both ch Driven
RL=4Ω, f=1kHz
10 100
Output Power [W]
Protection Circuit
The PC limiter circuit
operates to protect the power
transistors.
Warning by the TEMP
indicator.
The thermal protection circuit
operates to protect the power
transistors.
The relay operates to protect
the speaker system.
1k