On rare occasions the M A Series III will give a clunking sound when a cutting operation is performed.
Solution :- oil your machine - see oiling
Also note:- Some new machines will make a whirring sound when the handle is moved up and down. This is not a problem and will go away after a few days of hard work.
Photo with screwdriver
On even rarer occasions, the machine may JAM DOWN. If this occurs, do not attempt to un-jam with the handle. Please do thre following.
360deg a couple of times
Please note :- The problem is the result of insufficient oil and may occur on a new or used machine that has been sitting unused for quite some time.
Once un-jammed please oil well, and using the handle rotate the cutting head 360deg a couple of times then re-oil and repeat.
Also Note:- A new machine can also jam, To minimise the possibility, rotate as above before use for the first couple of weeks of service.
On brand new machines cut most work using the back part of the cutting board as shown below. Once the machine is fully "run-in" this cutting position should not be as important.
Also apply this rule to HEAVY DUTY CUTTING
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On older blue machines and early black (one part handle machines)
Please check and tighten the top dial lock screws occassionally
When correctly operating, the top dial must remain still when the head is spun from left to right .
Failure to keep the top scews tight may sometimes cause the top-dail to lock to the head .
Caution :- If you have the latest machine ( with this (2 part) handle) 
the following text does not apply.
Should you fail to keep the grub screws tight , under some circumstances the top dial may lock.
Top-dial (exploded view) 
(this view shown for clarity -- the screws never need to be removed.)
Should this happen :-
Release the 2 grub screws (anti-clockwise) about 2 to 3 turns only in the top dial (do not remove the grub screws as shown in the above photo.)
Then attempt to turn the top dial ( anti-clockwise) -- if it will not move -- employ a plumbers pipe wrench to release it .
Once releaced, tighten the Top-Dial again with fingers only to a soft touch (clockwise) then release the Top-dial anti-clockwise about 1/4 (one quarter) of one turn.
Now retighten the grub screws clockwise ( with the key) to very tight -- check reguralary to maintain tightness, this will prevent further lock-up.
