Common Dual Turntable Problems and How To Fix Them


Please note that I am not a repair tech myself, but we do have access to some of the best 
Dual technicians around. If we don't know the answer to your question, we certainly will
find someone that does know the answer!
These troubleshooting tips come directly from various 1200 series service manuals.
In addition what might work on a 1200 series turntable might not be correct for another
series   Not all of the troubleshooting tips that appear in the service manual appear here,
those that don't usually will require special tools or training.
If repairing your Dual turntable is beyond  your capabilities, please see a qualified repair
We have a list of these here.


Problem: Strobe Light does not illuminate
      Remedy:        Replace Strobe Lamp
                               No Power to turntable, check plug, wires and connections.
Problem:  Platter does not turn after activating the "Start Switch"
     Remedy:         Power supply to motor interupted. 
                               Drive pulley slackened. Adjust to specification or replace if needed.
                               If turntable has sat for a long time without being used, clean and relubricate.
                              Please review our Lubrication Points and Maintenance Page.
Problem:  Platter does not attain correct speed
     Remedy:         Drive pulley is not correct for current voltage, replace with correct
                              Excessive drive belt slippage, replace drive belt
                              Excessive friction in motor bearing or in rotor bearing assembly, clean
                             and oil bearings
                             Dirt on belt drive pulley.  Clean and try again.
Problem:  My turntable hums whenever I touch the tonearm.
     Remedy:         Make sure the ground wire from your turntable is connected to the "Ground"
                            or "GND" lug on the back of your amplifier.  If you don't have one of these,
                            run the ground wire to another source of ground, such as a cold water pipe,
                            conduit, etc.
Problem:   My turntable hums all the time.
    Remedy:         This is one of the most common problems with Dual turntables.  What is happening
                            is that corrosion sets in on the contacts within the turntable.  Here is how to fix this:
                            Using an emery board, very carefully clean the RCA plugs on the turntable or turntable
                            cables (or just replace the RCA cables). Then very carefully remove the wires one by
                            one from the cartridge and clean those up and carefully put the the wires back on.
                            While you have the headshell apart, clean the brass contacts at the head of the head
                            shell AND in the underside of the tonearm head where the headshell connects to the
                            tonearm.   Clean all contacts with a lint free cloth with Isopropyl Alcohol on it.  Your
                            hum should now be gone. You may want to cover the rest of the turntable with a cloth
                            so the grit from the emery board does not fall on it.
Problem:  Pickup head is not parallel to platter.
     Cause:          The pickup head has been moved out of position on the tonearm tube
                            during shipment, or rought handling. 
     Remedy:       Remove platter, using a screwdriver slacken screw on the pick up head
                            through the hole provided for this purpose in the chassis plate. Align the
                            pickup head and tighten the screw. 
Problem:   Pitch control stiff and difficult to turn
     Remedy:     Grease is old and has become stiff.  Clean all parts and relubricate with 
                         the correct lubricant.  Please review our maintenance page
Problem:   Stylus slips out of groove while playing record
     Remedy:        Tonearm is not balanced.  Balance Tonearm (see below)
                            Tonearm tracking force set too low, reset to cartridge manufacturers
                            Anti-skating control not set correctly, make sure it is set to the correct   
                            tracking force  and the correct stylus type. 
                            Stylus tip worn out, replace stylus.
                            Excessive tonearm bearing friction.  Adjust (see below)
Problem: When playing 78 RPM records, my Dual moves its tonearm back to the
                           tonearm rest before the record has finihed playing, or it won't return at all.
    Remedy:       It all depends how far you want to go with this.  What is happening is that
                          78 RPM records were not as precise as modern day recordings.  Lots of
                          times the centering hole on the record is not really dead center and this
                          can trip the auto return mechanism.  What you can do about this is have
                          your local Dual Repair Facility turn off the auto return until you are done
                          recording your 78's and then take the turntable back and have it reenabled,
                          or if you are handy and have the service manual you could do this yourself.
                          However this is a really delicate operation and if you mess it up, you can
                          quite easily damage or put your turntable so far out of whack that you will
                          need to send it off for repairs again.
Problem:Vertical tonearm movement shows resistance during set-down process.
     Remedy:   Tonearm bearing friction excessive.  Adjust (see below)
                         Lift pin sticks in guide tube.  Relubricate turntable according to
Problem: Tonearm does not set down at the correct point in automatic mode.
     Remedy:   Tonearm set-down point is incorrectly set.  Slide DUAL logo outward,
                         adjustment screw should now be revealed (later 1200's). Early 1200's
                         have this  screw under the speed control.  Set it to 45 RPM to reveal this
                         hole.  (122X series)
                         Friction face of tonearm coupling dirty.
                          Anti-Skating force set incorrectly. 
Problem: Tonearm returns to rest after manual set-down immediately after the platter
                      begins to  turn.
    Remedy:After fitting and each time after transport the unit should be started once
                      with the tonearm secured to the tonearm rest.  This will automatically adjust
                      the automatic shut off point.  For other models please consult your Service
                      Manual for the location of the set down adjustment screw.
                      Also, there is a plastic guide which wears down in the tone arm base and
                      needs to be replaced.  This is a pretty easy and cheap fix if you have a
                      Dual Service Manual for your turntable.
Adjustment of Tonearm:  This procedure is the same for all Dual turntables.
                    Proceed as follows: 
                      Set the tracking force to zero, set the anti-skating force to zero.  Turn the
                      weight at the back end of the tonearm until the entire tonearm assembly
                      is "floating" perfectly level to the top of the platter.  Now adjust the tracking
                      and anti-skating forces to the setting that is recommended by the cartridge
                      manufacturer.  If no anti-skating force is recommended, set it to the same
                      setting as your tracking force.  Your tonearm is now correctly adjusted. 
Adjustment of Tonearm Bearings:  
                      Both bearings must have a slight, just perceptible play.  Adjustment of the 
                      vertical bearing should be carried out by means of the left mounting screw
                      (inside horizontal screw on the tonearm rear assembly)  The horizontal
                      tonearm bearing is correctly adjusted  when at anti-skating setting 0.5
                     (tonearm previously balanced exactly) the tonearm  slides in without
                      resistance. The horizontal bearing adjustment screw is the one at
                      the top of the rear tonearm mount assembly in a vertical position.
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