jenn wrote:My 535 now backs off the dock about 4 inches then proceeds to just goes in circles. Is this the circle dance I read about in here?
No, but "going in circles" is part of the circle dances.
I thought that was only happening to the 4xx models?!
That's good thinking, keep it up!
I'll provide some detailed info, but can't provide any useful repair advice which you could DIY.
It would be useful for you to have explained where about the 535 is pivoting -- viz., is it pivoting about a stalled drive-wheel, or is it pivoting about the robot's center?
I'll assume it to be the latter, otherwise you might have described the 535 as crashing into its Home Base while gyrating through large arcs. Any other behavioral data could also be useful -- such as does the fault appear EVERY time 535 leaves the dock?
You have fair assurance that both drive-wheel motors
are functional, because both motors ran while reversing off the dock by "about 4 inches". That strongly suggests those wheel motors will both drive in the forward direction when commanded to do so (barring a faulty transistor-switch on the main-elex board). Following the back-off, the 535 spins through a large angle to select a forward-travel vector that will not intersect the HB.
My 535 then spins about body center
through 180-degrees and then heads straight away from the HB.
It is the 180-degree spin which your 535 seems to be caught in. That would suggest your 535's fault to be associated with the wheel-turns counting process (the only way a robot can do a neat 180-deg spin is to accurately know that both wheels rotated through the same angle). These 5XX machines use a magnetic based rotation sensor
(rather than the optical-based sensor that caused so much circle-dancing over all of Roomba's prior history) in the drive-wheel's module to generate rotation data which the machine's controller uses to keep track of wheel-speed and distance traveled. That magnetic system is immune to debris gathering on it!
Now that you know about the drive-wheel rotation sensor, I might point out that yours must have been working properly as Roomba reversed four inches away from the HB's dock! So what could have changed in the drive-wheel module between the reverse operation and engaging the 180-deg spin? Nothing I can imagine! You see? I have talked myself out of your 535 having any problem! Fault choices are not obvious.
How can I fix this behavior?
Additional information might be of help, otherwise: Call iRbt's Customer Support.