LG Dishwasher not cleaning well

I have a LG dishwasher that has suddenly stopped cleaning well and is leaving a film of soap on everything. We have been very good about running cleaners thru it ever so often as well as running vinegar thru it at least once a month. Any suggestions on where to start looking for problems. thanks
serial number is 904kwdj01930
model number is LDF6920ST

gr8filed said:
I have a LG dishwasher that has suddenly stopped cleaning well and is leaving a film of soap on everything. We have been very good about running cleaners thru it ever so often as well as running vinegar thru it at least once a month. Any suggestions on where to start looking for problems. thanks
serial number is 904kwdj01930
model number is LDF6920ST
I have a LG LDF6920ST dishwasher. It began to wash poorly, had an odor and left soap on dishes. I read the forums and learned that replacing the sump assembly would fix the problem. It did. The sump assembly cost about $140 and I installed the unit. Works great. That said, I investigated what the problem was in the sump assembly I had removed. There is a small flap that creates a one-way valve ([COLOR=black][FONT=&quot]LG Electronics 5220ED4004A Dishwasher Check Valve Flap) that had torn. It was less than five dollars to purchase. As I did not pay a serviceman to repair the unit I got away cheap, but really?!
Okay, so I sent an email to LG and thought they would inform people and save customers hundreds of dollars. Their response was to point out that my warranty had expired and repairs were at my expense.[/FONT][/COLOR]