LG 42pc1d Partial Black screen

[Ramis101]

Hi All,  
I've just been given this screen to fix so i don't know how long the problem onset was.

What I have is a partal black screen.  If set to analogue i/p (so i can see the snow) all but the left hand side of screen is black. as it warms up (5 to 10 mins) the black receeds until approx a 1/3 of the left is visable picture and a little bit starts to bleed in from the R also.

the transistion between black and snow is not a line ie geometric shape but a sort of zig zag.
My first look showed 9 3300uf 10V caps on main board had blown, so i replaced all of them - that made no difference.

I'm guessing at a dry joint somewhere (was it changes over time) but being as i'm a bit of a noob at plasma's I thought i would see if anyone had any ideas on here. while i'm waiting i'll check the other caps on the main psu board just in case.
(the 4 really large ones were OK when measured (450v 270uf & 250v 820uf))

Cheers all.

RR

Update:
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Managed to give it a known i/p.  Picture is distorted in colours, a bit 'dim' and splodges of black are sustained longer than they should be.  I'm thinking y-sus?
I can attach a picture if it helps
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