Hyundai HPT4260 - nearly fixed last bit of help needed please!!

[Dutchio]

Hi all ive had this plasma in my room for years with no issues. A few weeks back the picture went black and all I had was audio. Then it started to turn itself off. I replaced the vsus board and I got a picture again but it was multicolored dull and hard to make out with thin vertical black lines even the digital menu screens. I then replaced the control board. Still a similar issue. There are only about two boards left any idea what's causing the poor picture? I've only spent about 40 quid so far to revive it so I don't mind one last punt before I commit it's body to the ground. Any help or advice on my next step please anyone? Thanks!!