How to know what numbers mean that are in the black box in middle of screen?

This could be one of several different problems. The MOST common cause of complaints of characters appearing in a black box in center of screen that we see @ my service center is due to customer having the "text" option of the closed-captioning feature enabled (often, inadvertently; navigating the on-screen menus and employing the multiple feature options of modern TV's can be problematic for even the most well-versed of us!); the user can readily tell if this is the source of the complaint by noting whether the characters displayed change from channel to channel, as they will if the display in question is simply the text function of closed-captioning. It is also possible that the display is an indication of the unit being in the "service mode", which is a feature employed by service technicians in diagnosing & repairing the set. More descriptive information on exactly what is being displayed---i.e., the size of the box being seen, exactly what characters are shown, etc.---would be helpful in determining just what this problem is about...perhaps p2412 could post a picture of what is being displayed?