STEREO INTEGRATED AMPLIFIER RA-985BX
The RA-985BX has both thermal and over-current protection cir-
cuitry that protects the amplifier against damage in the event of
extreme or faulty operating conditions. The protection circuits are
independent of the audio signal and have no impact on sonic per-
formance. Instead, the protection circuits monitor the tempera-
ture of the output devices and shut down the amplifier if
temperatures exceed safe limits.
Most difficulties in audio systems are the result of incorrect con-
nections, or improper control settings. If you encounter problems,
isolate the area of the difficulty, check the control settings, deter-
mine the cause of the fault and make the necessary changes. If
you are unable to get sound from the RA-985BX, refer to the sug-
gestions for the following conditions:
Standby Power Indicator Is Not Lit
Most likely, you will never see this protection circuitry in action.
However, should a faulty condition arise, the amplifier will stop
playing and the LED indicator on the front panel will light up.
The Standby Power Indicator should be lit whenever the RA-
985BX is plugged into the wall power outlet. If it does not light,
test the power outlet with another electrical device, such as a
lamp. Be sure the power outlet being used is not controlled by a
switch that has been turned off.
If this happens, turn the amplifier off. Let it cool down for several
minutes, and attempt to identify and correct the problem that
caused the protection circuitry to engage. When you turn the am-
plifier back on, the protection circuit will automatically reset and
the indicator LED should go out.
If another electrical device works when plugged into the power
outlet, but the Standby Indicator still will not light when the
RA-985 is plugged into the wall outlet, it indicates that the internal
power fuse may have blown. If you believe this has happened,
contact your authorized Rotel dealer to get the fuse replaced.
In most cases, the protection circuitry activates because of a fault
condition such as shorted speaker wires, or inadequate ventila-
tion leading to an overheating condition. In very rare cases, highly
reactive or extremely low impedance speaker loads could cause
the protection circuit to engage.
If the protection circuitry triggers repeatedly and you are unable
to isolate and correct the faulty condition, contact your authorized
Rotel dealer for assistance in troubleshooting.
Check the signal source to see if it is functioning properly. Make sure
the cables from the signal source to the RA-985BX inputs are con-
nected properly. Be sure the Listening Selector is set to the proper
input. Check the wiring between the RA-985BX and the speakers.
Protection Indicator Is Lit
The front panel indicator lights when the RA-985BX protection cir-
cuits have shut off the amplifier. Typically, this occurs only when the
ventilation openings are blocked, when there is faulty speaker wiring,
or after a period of extreme use. Turn off the system and wait for the
amp to cool. Then push the front panel power switch in and out to
reset the protection devices. If the problem is not corrected or re-
occurs, there is a problem with the system or the amplifier itself.