Television and Home Theater

Can you help me with a problem? I am starting to get some blue lines running kind of vertically through the screen, visible when there is a dark background. Can you tell me what this is and can it be fixed? 

I have to say this has been a good TV, this is the only problem Iv'e had with it since I bought it maybe 13-14 yrs ago. 

Got the TV for free. The lady said it just stopped working one day. No noises, just quit.....she said. I opened it up and the power fuse is good. I pulled the power supply board out and inspected the back. Everything looks Ok with no testing.

 I know this is not much to work with, but I was hoping someone good point me in the right direction. Going to pull out my meter tonight and do some testing.

Thanks a lot,

 Brad

looking for service manual and part numbers of ics for the above model found service manual for

kp-51ws500 and was wondering if they are the same even though that model number is not listed

on the cover? picture appears concave with pink and green shadows  please help thank you dawn