Roomba 570 problems

[ddl@danlan.*com (Dan Lanciani)]

I decided it was finally time to try a Roomba so I got a 570 from
Hammacher Schlemmer.  It worked for about an hour total and then
one of the wheel modules seemed to lose the ability to move in a
forward direction.  This made the Roomba turn in a tight circle
until it gave up.  There was nothing obviously mechanically wrong
with the wheel module (it turned freely by hand) and when the Roomba
tried to turn it the wheel did stiffen up (as determined by my hand).
Maybe part of a bridge driver had failed?  Anyway, Hammacher Schlemmer
exchanged the whole package for a new one.

The second Roomba also worked for about an hour total and then started
asking me to remove and clean its brushes.  Which I did.  Repeatedly.
Peering underneath I could see that the brushes were not turning at
all.  I made one more thorough cleaning and made sure that the brushes
rotate freely by hand.  Still they do not run and Roomba asks me to
remove and clean them every two minutes.  I suspect the motor is just
not getting power.

Am I having really bad luck or is this typical?  Could iRobot have
gotten a bad batch of power transistors?  I assume I can get another
replacement from Hammacher Schlemmer, though I don't know how many
times they will pay the shipping...

				Dan Lanciani
				ddl@danlan.*com