Ok. The 280 is a simple cleaner as far as the drive components are concerned. If there is no or little pressure coming from the jets that suck debris up than you will need to look at a couple things.
-First thing is that you can take a paper clip and bend it to poke into those jet holes. This will remove any lodged debri and may take a couple times because there may be more debri in the line.
-There is a single screw that holds the top housing on the cleaner. If you take this off you can clean the jet inside the cleaner that actually drives it around the pool!
Remember, there is always a source problem when things like this arise. In this case, it would be debris bypassing your main pool filter. Keep an eye on that little screen that is in the wall connection for your cleaner. If it is dirty go ahead and clean it if there is debris in there. Make sure the little screen is in good condition and has no broken screen. Lastly, watch that screen for a week or so and see how often it gets dirty. If it is getting dirty very quickly than your sorce issue is with your main pool filter letting dirt or debris back into the pool.
-DrH2O