We have had our KDF 55 WF655 set for 5 years and replace a bulb about 12 months ago but not the pixels have gone bad showing a blue shadow and now, even worse the center of the screen shows a green hole

try t0 restore factory settings..

hello my is rico i work on tvs sometimes, it looks like you have bad lamp or your cooling system is work properly maybe thermal sersor. if need help fixing your tv let me know feel free to call me at 602-810-7149 anytime.

The blue shadow is a sign of a bad light engine. this is a common problem for this model. Fixing this type of problem is quite expensive. Light engine Costs you several hundred of dollars nearly to the price of new TV set.

OK...Did you replace the lamp with a Sony original? If you did, then carefully check that the door is closed properly.

this is caused by the optical block going bad and needing replaced contact sony tech support

You have a bad light engine call Sony and see if it might be on their extended warranty list.

Sounds like your light engine is going

light engine will be the problem

replace the optical (light engine assy)

On the KDFE55A20 this sounds like a bad Q-Box. I would get an estimate from a Sony authorized servicer as this part may be quite expensive. On the 55A10 model this may be the B-Block and is also quite expensive. Getting an on-sit estimate would be the first step I suggest. Again go with an authorized Sony servicer. Call Sony or go to Sony.com for customer service. Good Luck