how to unstick bump sensor on 4230 schedular?

Gernith · Joined: 20 Dec 2005 Posts: 15

My roomba started acting crazy, and the diagnotic tests say the right bumper sensor is stuck on. How can I unstick the sensor? Are there any take down instructions on the web somewhere? Can someone point me in a direction to look?

Thanks

vic7767 · Joined: 14 Jan 2006 Posts: 3270 Location: Louisiana

You can try tapping your front bumper 10 to 15 times and see if you can dislodge the debris. If not you can go to this URL and read about the teardown instructions:

http://www.roombaexchange.com/roombatd.php

Gordon

Gernith wrote: ...the diagnotic tests say the right bumper sensor is stuck on. How can I unstick the sensor? If vic7767's suggested dirt-clearing tapping fails to overcome the problem, you may have to dismount the Bumper and search for mechanical features that it may be touching, and thus dragging against.

I know of one such case, because I induced it myself! (details here). I had noticed some Discos were using a screwed-down disc, at top of a tall chassis-post on the robot's right-side, to retain a local wire-bundle, so, after doing some work that disrupted my wire bundle's hot-melt-glue tie-down, I decided to secure the cable with screw and washer.

It worked fine for awhile, but eventually the inner, top surface of the Bumper began to drag against the screw-head. The drag got severe enough to overcome the spring-force used to push the Bumper to its forward position. Inspection of the Bumper revealed slight scratch marks caused by the screw.

Over long-term use of Roomba, the bumper-linkage joints can wear enough to cause slight sagging of the Bumper-shell; hence, close-spaced (in vertical direction) fixed & moving parts may have lost the clearance that once allowed unrestricted motion. IOW, if your Disco uses the screw & washer cable hold-down in that tall post, its screw-head may be restricting Bumper-shell movement. Quote: Are there any take down instructions on the web somewhere?... Try this document.

richnorto · Joined: 03 Sep 2007 Posts: 256

I replaced the bumper on a roomba and it was not too difficult. Mine had a warp in the removed bumper post - noticed after surgery - which had caused the right bumper to constantly stick.