I have been working with LG Plasma products since they were introduced, and as dealers have a good relationship with them. I am only too aware of the y-sus issues with them, and, to a lesser degree the z-sus and ctrl pcb. Repairs to the y-sus pcbs are mixed, unless the drive i.c. (stk) has failed, i manage to recover about 50% of these throughout the current range, pc55 and pc56. Enough of me, current problems are this, why do plasmas give out a deafening buzz with no picture, scope checks are ok, every pcb is changed, y-sus, ctrl, z-sus, y-drv and z drive and psu. these are brand new tv,s. I am fully aware that the ctrl pcb has to be carefully matched to the screen. i dont know where to go next, screen???
i am able, free of charge to supply any hitachi,toshiba, sharp or lg service updates and manuals, i also have eeprom dumps for these sets also, uk only, as we are dealers for these companies, hope this helps, can you help me pls, thanks, tony walker