The Dirt Dog as well as other R2 model Roombas are no longer being built and offered to the Public. In an effort to extend the operational life of these robots the following modification procedures are presented for your information
One of the major early conditions that develop on the R2 Roombas has to do with the User Interface, ( UI ). That's a fancy description for the pushing of the Clean button or other buttons on top of the Roomba that tell it to do something
Since this machine is given the task of cleaning the floor it is exposed to a variety of different subsets of debris. None of which are actually blocked from entering a multitude of internal areas of the Dirt Dog that eventually cause its demise. We are going to perform a couple of mods to the Dirt Dog to prevent the entry of debris into the UI as well as the brush gear assembly.
The telltale sign of UI failure is very easy to spot. You press the Clean button on top of the Dirt Dog and absolutely nothing happens. You suspect the battery, change it out for a good one and still no go. You grab your remote control, press the Clean button and lo and behold, the Dirt Dog plays its start up tune and starts a cleaning session. Now we have a place to start our investigation. If you refer back to the "Dirt Dog Dis-assembly" page you will see how to remove the top portion that contains the Clean button.
Now lets flip this top over and see what type of mechanical components are used to protect the UI button from damage.
Now lets take the 7 screws out and see what's there.
As you can now see, debris has entered inside the cover under the shell and built up an electrical shield that prevents operation of the Clean button. All that dust and dust has now prevented electrial contact of the black conductive circles in the underside of the Clean button from being able to close the circuit on the small printed circuit board. At this point the oval silicone Clean button can be removed and gently washed with a mild detergent and allowed to dry and the circuit board can be cleaned using a Q-Tip and a drop of alcohol.
OK, so how did that stuff get into the underside of the button assembly ? A close inspection of the black plastic cover with the 7 screws reveals that there is not a good seal between it and the upper shell it attaches to. Also the ribbon cable that exits the black cover also was not properly sealed to prevent the entry of debris. We shall now begin our MOD !
To enhance a good seal on each of the 7 screw openings that are used to hold the black UI cover in place required that each screw hole be re-tapped with a flat bottom 4-40 tap. Once that was done then all 7 screw openings need to be modified by using a drill bit to add a little taper to the top opening. This taper allows the new 1/4 screws to seat better and provide a tight seal. It is best to do the taper effort by hand because using an electric drill may do more than provide a taper, you might wind up with a hole that is too large.
At this point Clear Silicone sealant becomes your friend. Apply it to all exposed edges of the black plastic cover and also apply to the Clean button.
Clear Silicone sealant is applied to the opening in the top cover that the Clean button assembly mounts to.
Now the UI is completely sealed from the entry of debris into the Clean button and circuit board.
Next we will mod the brush deck gear assembly to keep out more nasty things.