Hold down the Menu and Input keys until it gives you a flashing two-digit code. That should direct your servicer in right direction.
If you're comfortable going into the set (unplugged of course), and know how to use a meter, check pico fuses F5A04 and F5A05 on the Power board (center one). If either of those are tripped, you have a convergence issue. You would either need the solder checked on the chips, or the chips replaced.