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14

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.

Protection Circuit

Remedy

Possible Cause

Indicator

CLIP indicator lights up

PROTECTION indicator 
lights up

There is a short at the 
amplifier’s speaker 
outputs, the speaker’s 
inputs, or in the wiring.

The impedance of the 
connected speaker 
is too low.

The heat sink temperature 
has exceeded 90

°

C.

A DC voltage of 

±

2 V 

or greater was detected 
in the amplifier’s output 
circuit.

Locate and remove 
the short.

Check the ventilation 
around the amplifier 
and improve the airflow 
if necessary.

Consult your dealer 
or a Yamaha service 
center.

The PC limiter circuit 
activates to protect 
the power transistors.

The thermal protection 
circuit activates to 
protect the power 
transistors.

The output relay activates 
to protect the speaker 
system.

Use a speaker with a 
minimum impedance 
of 4

 (8

 in Bridge 

mode).

PC9500N

PC4800N

1

10

100

1000

10000

1

10

100

1000

10000

Output Power[W]

Power consumption[W]

Power consumption[W]

Power Consumption[W]

Mode:STEREO
Both ch

Output Power[W]

Power Consumption[W]

Mode:STEREO
Both ch

1

10

100

1000

10000

1

10

100

1000

Performance graph

Summary of Contents for PC4800N

Page 1: ...POWER AMPLIFIER Owner s Manual E ...

Page 2: ...h FCC regulations does not guarantee that interference will not occur in all installations If this product is found to be the source of interference which can be determined by turning the unit OFF and ON please try to eliminate the problem by using one of the following measures Relocate either this product or the device that is being affected by the interference Utilize power outlets that are on d...

Page 3: ...k If you think internal inspection maintenance or repair is necessary contact your dealer Do not modify the unit Doing so is a fire and electrical shock hazard If lightning begins to occur turn off the power switch of the unit as soon as possible and unplug the power cable plug from the electrical outlet If there is a possibility of lightning do not touch the power cable plug if it is still connec...

Page 4: ...tch off remove the power plug from the AC outlet and remove all connecting cables Damaged cables may cause fire or electrical shock Allow enough free space around the unit for normal ventila tion This should be 5 cm at the sides 10 cm behind and 10 cm above For normal ventilation during use remove the rear of the rack or open a ventilation hole If the airflow is not adequate the unit will heat up ...

Page 5: ...below 40 Hz and detented attenuators and level meters for channels A and B are provided Metering and indicators include easily visible two channel level meters a PROTECTION indicator that shows the state of various protection systems power on off detection output protection DC detection a TEMP indicator that indicates heat sink overheating and a REMOTE indicator that indicates the external remote ...

Page 6: ...rmal operation If a DC voltage is detected at the amplifier s outputs Turn off the power and then turn the power back on again If the amplifier overheats When this occurs the TEMP indicator will be lit You should turn off the amplifier and allow it time to cool down See the Precautions section of this Owner s Manual for ways to prevent the amplifier overheating 4 TEMP indicator This indicator will...

Page 7: ...ng a 12 dB octave high pass filter 4 SPEAKERS jacks These are Speakon type output jacks Speakon type cable plugs can be connected here These are five way binding post output jacks 5 6 8 9 4 1 7 2 3 5 DATA ports An external control unit or interface box can be connected here to monitor or control the amplifier from the external device 6 AMP ID switch When an external control unit is connected to th...

Page 8: ...er of speakers that are connected Refer to the following diagrams and make sure that the speaker impedance is not less than the value prescribed for each type of connection Connections in BRIDGE mode Speaker min 8Ω When using the Speakon connector Speaker min 8Ω Use the 1 and 2 pins of the 2 jack Connections in STEREO PARALLEL modes Speaker min 4Ω Speaker min 4Ω or ...

Page 9: ...peaker terminals Screw 3 After removing approx 15 mm of insulation from the ends of the speaker cables pass the bare ends of the speaker wires through the holes in the corresponding speaker terminals and tighten the terminals to securely clamp the wires Refer to page 8 for speaker polarity 15mm Shown actual size At this time make sure that the bare ends of the speaker cables do not extend from the...

Page 10: ...e rear panel of the rack and the rear panel of the amplifier Fan Use a fan with 1 5 m3 min or more maximum wind and 5 mmH2 O or more maximum static pressure Mounting Install the fan kit on the top slot or the top panel of the rack and install a blanking panel between two amps If the unit is rack mounted and transported frequently we recommend that the rear of the unit be supported by fitting a pai...

Page 11: ...Power into 8Ω 9 dB 6 dB Voltage Gain Vol max 32 dB Input Impedance 30 kΩ Balanced 15 kΩ Unbalanced Controls Front Panel POWER switch ON OFF Volume 31 position ch Rear Panel MODE switch STEREO BRIDGE PARALLEL HPFswitch ON OFF fc 40 Hz 12dB octave DIP switch 6P Connectors Input XLR 3 31 type ch Euroblock connector ch Output SPEAKON ch 5 way binding posts NETWORK RJ45 x 2 POWER AC INLET Indicators PO...

Page 12: ...12 Block Diagram ...

Page 13: ...13 Dimensions Unit mm 480 88 456 46 4 380 26 25 30 370 30 25 ...

Page 14: ...ted in the amplifier s output circuit Locate and remove the short Check the ventilation around the amplifier and improve the airflow if necessary Consult your dealer or a Yamaha service center The PC limiter circuit activates to protect the power transistors The thermal protection circuit activates to protect the power transistors The output relay activates to protect the speaker system Use a spea...

Page 15: ......

Page 16: ...YAMAHA CORPORATION V853450 R11 AP 16 Pro Audio Digital Musical Instrument Division P O Box 3 Hamamatsu 430 8651 Japan NP Printed in Taiwan ...

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