Do you have a users manual for a Hamilton Beach hand blender?

Hamilton Beach, a light manufacturing company based in China, makes a line of inexpensive, good quality kitchen appliances, which are in general well-designed and assembled from well-made parts; however, the assembly process has quality control problems, with the result that it may be necessary to open the casing of a purchased appliance to correct an assembly error. Sadly, Hamilton Beach declines to provide users manuals to allow purchasers to do so safely, claiming (not very believably, in my view) that this information is proprietary. In particular, I have purchased a Hamilton Beach model 59780R hand blender which suffers from intermittent failures, the symptoms of which suggest that the power switch is sound but improperly installed, in that one or more of the screws fastening it to the casing need tightening. Is there any information available as to how to open and reseal the casing of this appliance without damaging it in the process? I expect the repair itself to be straightforward, and am not concerned with warranty issues.

It appears that I am looking for a service manual; the users manual to be found at the Hamilton Beach web site has no useful content with respect to servicing or repair of the device. Essentially, I would like to know how to nondestructively open the casing of the hand blender for servicing, which I expect, from the indications, to consist mainly of correcting one or more assembly errors, and to close it again when I am finished. I have had some very frustrating email communications with Hamilton Beach customer service, in which they told me that their principle, presumably somewhere in China, does not allow them to provide this information, claiming that it is proprietary.