2
nd
June 1999
Page11 Copyright © 1999 Linn Products Limited. All rights reserved.
Contents
Amplifier & Audio Problems
The following are some problems you may encounter with the audio output of theLK85 or LK140.
It is assumed at this point that it is definitely the LK85 or LK140 that is causing the problem and you have
ruled out all other aspects of the system. If you have not – please do so before proceeding.
Amplifier & Audio problems
Symptom Circumstances Possible Cause(s) Cure
No output from
one or both
channels.
May be
accompanied by
a popping or
buzzing noise.
Probably constant.
Ensure, however,
that the amp is not
tripped and is not in
Standby (See Trip
and Standby
sections above)
Monolithic IC(s) (U100,
U101, U200, U201) blown.
Please note – U100 & U201
are only fitted to the LK140
It is advisable to replace the
entire board, as blown
monolithics often destabilise the
board – repair is not normally
reliable.
Clicking, buzzing
or popping noise
at output of both
channels.
May be intermittent,
but probably
constant
Links at P10 & P11
connectors (found at left-
hand edge of board, roughly
½ way back) fitted at wrong
position or fitted when they
should not be.
The only link fitted should be
shorting together the two pins
marked ‘Fit after burn-in’. All
other pins should be left unlinked.
Output is mono,
not stereo – even
if balance is
adjusted on pre-
amp, output of
both channels of
power amp
remain equal.
May be intermittent,
but probably
constant
Links at P10 & P11
connectors (found at left-
hand edge of board, roughly
½ way back) fitted at wrong
position or fitted when they
should not be.
The only link fitted should be
shorting together the two pins
marked ‘Fit after burn-in’. All
other pins should be left unlinked.
Thumping/
banging noise
through speakers
when switching
between inputs of
pre-amp
May be intermittent,
but probably
constant
Links at P10 & P11
connectors (found at left-
hand edge of board, roughly
½ way back) fitted at wrong
position or fitted when they
should not be.
The only link fitted should be
shorting together the two pins
marked ‘Fit after burn-in’. All
other pins should be left unlinked.
DC at the output
Symptom Circumstances Possible Cause(s) Cure
DC (around 2V)
at the output of
both channels.
Only happens when
unit is not
connected to
speakers and/or
pre-amp.
This is normal and causes no
problem, as the fault only
occurs when the amp is not
connected to anything. As
soon as the input/output is
connected, the DC
disappears.
No cure necessary.
DC voltage at the
output of one or
both channels
Probably constant Monolithic IC(s) (U100,
U101, U200, U201) blown.
Please note – U100 & U201
are only fitted to the LK140
It is advisable to replace the
entire board, as blown
monolithics often destabilise the
board – repair is not normally
reliable.
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