Sony KP51WS500 Problems

When my friend gave me this set, it was working fine.  After getting it home and plugging it in, I first pressed the "Flash Focus" button as suggested by my friend.  Everything was fine, so I unplugged the set until I could move out my old set.  The next day, when I reconnected the Sony KP51WS500 set to my digital converter box and plugged it in, the screen has only the three primary colors (Red, Blue, & Green) and also the picture is distorted (the top of the picture is bowed downward).  I've tried the "Flash Focus" again to no avail.  In reading some threads in this forum, it looks like a problem with the convergence board 'D'.  I've found a new board for $177 bucks.  I'm not 100% sure that this is the fix???  I don't have a lot of money to gamble, but would really like to get this set working.  Any input would be much appreciated.  Thanks,  pchadwell.