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:
/
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
/

[tom66]

Would you say image has a purple/lilac tinge?

With the TV unplugged, check both fuses on the Z-sustain, both are probably blown. If this is the case, then the hybrid may be shorted, but you can try putting some new fuses in there and seeing if they blow immediately. Otherwise, you need to replace the hybrid, or the Z-sustain.