I recently figured out how to get into the service menu for my rca tv, model # f31317. I was able to change p11 to 53 to do the anamorphic squeeze trick and also changed p6 and p7 to correct the fishbowl effect that occured when I squeezed the image. I was wondering if someone with knowledge of the service menu could give me some hints as to how to fix a picture problem I am unable to solve with the television's regular picture adjustments. I believe the problem is what others here have referred to as being unable to hold black. The problem is most easily seen when watching letterbox movies. The letterbox bars shift color from dark black during bright scenes to dark grey during dark or nightime scenes. Daylight scenes in movies produce deep eye pleasing blacks while during night scenes blacks are all varying shades of dark grey. If someone could point me too some settings I could try tweaking I would greatly appreciate it.