Check to see if the unit is plugged in or not. Oftentimes, the simplest step is also the most neglected one.
If the unit is plugged in and still seems to be unresponsive, press the "power" button.
If it's still not working, call a tech to come and service the unit.
If your unit shakes excessively:
Double check that you removed the shipping bolts from the back of the unit (instructions on how to do this should be listed in the product manual)
The load is unbalanced. Make sure to separate fabrics by similarity when dividing up your loads. An imbalance in the fabrics within the drum tend to make it shake more than usual.
Make certain unit is placed on a level surface and that all four feet of the unit are making full contact with the floor.
If your clothes come out wrinkly:
Make sure your load is large enough to fill the drum to 2/3 of its capacity. If it's not full enough, it will toss your clothing around more than it should and causes the unit to extract too much water from the load during the final spin cycle in the washing process.
If your clothes feel wet after the dry cycle:
Because combination washer dryers use condensation drying, it will seem as though everything is still damp when you initially reach inside the drum to remove your load. Actually take your items out one-by-one when removing them from the humidity of the dryer. If they don't feel dry within 10 to 15 seconds, then place them back inside the unit to continue the drying cycle.
Using the self-cleaning feature
If your unit has a self-cleaning feature, you should use the feature once every six months to avoid soapy residue and build-up within the unit. Please note: The drain screen in the lower right corner must be cleaned periodically to prevent a build-up of lint or other foreign matter. With unit empty and off, turn wash selector to the final spin of the regular wash cycle. Turn unit on and wait for it to begin spinning. Remove the drain screen during this spin cycle, clean and replace before cycle stops. This will prevent residual water from running out of the unit and onto the floor. Turn unit off and reset for the next wash.