Error hp 6110 carriage jam

My HP 6110 all in one is printing slanted prints and showing the error message open door and clear carriage jam. Ive been through the HP help info to no avail. Is there anything I can do without taking it in for service?

The proper nomenclature is "encoder strip". Its a clear plastic strip with lines on it that runs through the back of the cartridge assembly and hooks on at either end of the printer. I use Window Cleaner on a paper towel as it works better than the 30% water solution that Chris recommended. Alcohol actually has little or no effect on ink.