Troubleshooting Guide - NAD 705 Service Manual

TROUBLESHOOTING GUIDE
CIRCUIT
I
SYMPTOM
CAUSE
REMEDY
Defective ON/OFF switch .
Replace or repair as required .
Defective band selector switch .
Replace or repair as required .
NO SOUND (Unit
Defective volume control .
Check volume control resistance
GENERAL
does not work at all)
for continuous operation.
Replace if necessary .
Defective speaker.
Replace speaker.
Defective speaker jack .
Replace or repair jack .
Defective band selector switch .
Replace or repair switch .
Defect in I FT T407
Check voltage and current for this
circuit .
NO SOUND
I
Open circuit of AM I F
Check resistance .
transformer .
Defective AM ant. coil, or OSC.
Replace if necessary.
coil .
AM
IF tuning faulty.
Readjust (see Alignment instruc-
tions) .
R F tracking faulty . Readjust (see Alignment instruc-
WEAK SOUND
tions) .
(Low sensitivity)
Defective IC401
Check voltages .
Replace if necessary.
Poor contact in antenna circuit.
Check resistance .
and resolder.
Defective band selector switch .
Replace or repair the switch .
NO SOUND
Open circuit of FM ant. coil,
Check resistance.
or OSC. coil .
Replace if necessary.
FM
Defect in FM tuner circuit. Check R F, IF and detector circuit.
eNo FM MPX
Check voltage and current of
transistors.
separation
Replace parts if necessary and
*No stereo
WEAK SOUND
readjust FM tuner.
light or FM
stereo does
(Low sensitivity)
I F tuning faulty.
Check the function of IC401.
not work
RF tracking faulty.
Readjust (see Alignment instruc-
tions) .
Defective I C401
I
Check voltage and current.
Poor contact in FM antenna
I
Resolder or repair as required .
circuit .