Jeff Rowland Design Group Model 2 - Manual (Page 15)

Basic Troubleshooting
A summary of fault conditions, their causes and remedies, are listed below.
The Model 2 Amplifier can produce high power levels which, without well designed protection circuitry, could damage loudspeakers. Therefore, most fault
conditions which may occur during use will be indicated by the Model 2 reverting to a standby condition.
JRDG = Jeff Rowland Design Group, Inc.
Condition
FRONT PANEL STANDBY/POWER button lamp
does not illuminate after pressing, although the
Amplifier operates normally.
FRONT PANEL STANDBY/POWER button lamp
does not illuminate after pressing, and Amplifier
does not operate normally.
FRONT PANEL STANDBY/POWER button reverts
to standby condition during listening but can be
returned to operational condition.
Cause
Light bulb defective.
Incorrect power connections or AC MAINS
CIRCUIT BREAKER on Amplifier rear panel is
tripped.
Abnormal operation of Model 2 Amplifier internal
circuitry.
Excessive sub-sonic signals produced by source
components.
Severe clipping of Amplifier circuitry under
intermittent overload conditions.
Remedy
Remove STANDBY/POWER button from front panel
and replace bulb located under button. Use
replacement bulb kit and instructions supplied by
JRDG.
Review Installation/Rear Panel Power Connections
section. Reset CIRCUIT BREAKER on amplifier rear
panel.
Consult dealer or JRDG.
Repair or replace source component (preamplifier).
Identify and correct abnormal conditions such as low
frequency rumble and/or acoustic feedback caused
by phono playback components (if applicable).
Reduce volume slightly or use higher efficiency
loudspeakers.