Bosch PRM-4P600 - Troubleshooting

28 en | Troubleshooting Power amplifier
2023-01 | V02 | F.01U.402.247
Installation manual
Bosch Security Systems B.V.
7 Troubleshooting
Problem Possible cause Solution
Amplifier does not turn on
and power LED is not
illuminated.
Power (plug) disconnected or
the power source is giving
insufficient power to the
device.
Ensure power cord is securely
connected to device and
check the power from the
mains.
Power button LED is
continuously blinking.
Start‑up fault. Contact service agent.
No audio signal (no front
panel LED indication).
1) Audio input cable has
come loose or has not been
properly plugged in.
2) Input source is not sending
signal or sufficient signal.
3) Input level is turned down.
1) Check that the cables for
any damage.
Check that the cables are
installed and wired correctly.
Check that the wires are
secured inside the connector,
and the connector is fully
plugged in and seated
securely to the amplifier.
2) Ensure that the input is
turned up.
No audio is coming out of the
speakers, but the input LED
indication shows there is
signal.
1) Output speaker cable has
come loose or has not been
properly plugged in.
2) Maybe there is a pilot tone
present.
1) Check that the cables for
any damage.
Check that the cables are
installed and wired correctly.
Check that the wires are
secured inside the connector,
and the connector is fully
plugged in and seated
securely to the amplifier.
2) Pilot tone will usually not
be audible, but the amplifier
is still working correctly.
Audio sounds distorted. 1) Input level is too high or
too low.
2) Clipping of input stage.
3) Music source is of poor
quality.
4) The amplifier is being
overdriven by exceeding the
max. output allowed (i.e.
drained powerTANK).
1) Ensure that the source
level is not too high or too
low. This could mean
re‑adjusting the level on the
amplifier.
2) Check the quality of source
material.
3) Turn down or consider a
bigger amplifier.
Audio sounds very muffled or
lacks low frequencies.
Incorrect speaker settings are
activated (e.g. LP used with a
full range speaker).
Adjust the speaker settings
on the rear of the device and
ensure that the settings
match they types of speakers
used.