Strange Issue with brush slowing down on Discovery

c0mputerguru · Joined: 02 Jul 2008 Posts: 2

I've got an issue that searching on these awesome forums haven't found an answer for me.

I've got a discovery scheduler, and right after my move, it seemed to pick up a lot less stuff off my floor. I watched it one day, and it seemed to start out fine, but after a minute or two of running, there was an odd sound coming from the roomba, and it sounded like the brushes were slowing down, or sometimes just stopping completely. It would slow down for a couple seconds, pick up speed again, and then slow down again, and would continue for the rest of its cleaning cycle.

As a true believer of the scientific method, I thought, lets test this further. Maybe it was a loose connection, and bumping into walls was causing this. Nope. The brushes would change speed while going in a straight line across the room. Could it be a battery issue? Nope. Wheels are moving fine, everything else is working well, but the brushes slow down. Depleting and deep charging the battery doesn't do anything.

So I finally looked online, and found information about the diagnostics mode. Unfortunately, my roomba is already a little broken; the speaker stopped working a bit ago. So going through the diagnostics mode was hard, but I finally got to the brush motor part, and behold, the brush would exhibit the same behavior. It would run for a couple minutes, and then slow down. But there is now a new piece of information. Whenever the brush slows down, the spot light starts to flicker. However, looking online, I can't seem to find anything about this flickering light for this particular test.

This is where your help comes in. Does anyone know what the flickering light means? Is there a belt for the brushes like there is for the wheels that needs replacing? Could it be a voltage imbalance? Could it be that the motor itself is dying?

Please help me, my home is slowly getting dirty, and my poor roomba sounds like its in pain!

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

Since a warranty does not come into play here on your Roomba, you might consider disassembly and inspection of the brush gear box and brush motor reduction gear box. While you have it apart you can replace that speaker with one from Radio Shack that is just about the same size or you can order one from Chris and also use the disassembly instructions at the same site. www.RoombaExchange.com

c0mputerguru · Joined: 02 Jul 2008 Posts: 2

So I took my roomba apart this evening, and looks like you're right. It seems that the gear assembly behind the plate (not the one attached to the motor) was starting to go. In particular, the gear that the motor is connected to was not tightly spinning with the rest of the gears. Took a while to figure out that it was teh gear, did a lot of testing, but what finally made me come to this conclusion was that when I pushed the gear closer to the rest of the gears, it stopped making the squeeling sound that I was hearing when the roomba was together. I've ordered replacement gears (and a new speaker while the thing is apart) and I'll post back once I've put it back together.

But wow, it was really easy to get the thing apart, and boy was it dusty once it came apart!

Thanks for the help Vic!

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

Head down to your local auto parts store and pick up a tube of white lithium grease to lube those new gears with. While you're waiting go ahead and pull your wheels and clean and lube those gears also. You'll be suprised what you may find inside. :D