It's an 8 -10 year old Mitsubishi set. At least it looks like some kind of test pattern. The TV works great, performs outstanding except this black and white striped box is always on top of the beautiful picture.

Pattern goes away only while it switches inputs. Have tried factory and hard resets. Is there something corrupted in the firmware, eprom or whatever?

Is it trash? Are there any service codes to try?

Probably a bad circuit board or failing component.

Thanks for your input. Looks like Ill have to figure out the right thing to do with the carcass.