"Jeff Wisnia" wrote in message
. ..
Dimitrios Paskoudniakis wrote:
I have a Black&Decker electric hedge trimmer - you know the kind, with
the thumb safety, the index finger trigger, and the 2-3 ft long shears,
which operates on electrical power from a cord plugged into an outlet.

All of a sudden the unit keeps cutting off even with the trigger held.
The cord is firmly seated for electrical continuity. At one point I had
severed the power cord, repaired it, so was thinking it was the cord, but
even with a new replacement cord the symptom persists, and I do get the
intermittent brief "on" with the original cord. The original cord does
provide power for other things, so it is not the cord, but perhaps the
severing shorted something in the trimmer?

Here's the peculiarity: If I rotate the unit so that it is upside down,
it runs. As soon as I rotate it rightside up, it conks out again.

Any ideas as to what this is, and if it is easily repairable, or do I
just need to buy a new one?

My guess is that the brushes are worn down and the commutator is worn to a
slightly smaller diameter where they have been riding on it. When you flip
the unit over the armature may slide slightly endways within the limits of
the bearing spacing and bring the unworn portion of the commutator into
contact with the brushes, so it starts.

Brushes are easy and cheap to replace yourself. Check it out.

Good Luck,

Jeff

Yeah, that sounds right.