sony bravia kdl w804

[hamid1379]

hi
I bought this TV 19 month ago. when i connected it to PC with HDMI cable and watch the TV suddenly horizontal black and narrow lines appeared in whole screen. from left to middle of TV and disappears in right side. I disconect Pc but problem exist in all situation such as video input, digital tv, sat and etc. a tv repairman said that this is a epidemic problem in this model and because of lg panel that used in this tv . he said that can fix this problem for 600$  with repairing panel. is it true?I think he was lying. is this problem because of capacitors? how can i resolve this problem myself ? i have tools in home and Experience in electronics.  please help me and give  a tutorial manual for fix this problem in home.
thanks

[downunder]

Yes, this is a common problem with Sony. especially the 40inch, 46 inch and 52 inch models. It is caused by bad connection of the tab bonds for the flexicable at one end at the top of the panel. These flat cables are glued in place but one or more connections can lose contact.

You may strip the display panel (big job) and locate the poor bond by pressing down on the glued cable (picture will come good). Then you need to insert some packing between the faulty bond and the metal frame of the panel so that pressure is applied to the bond.

Unfortunately, I have to advise that I've been trying to repair these for years without success. Works OK on the day you repair it, then back to its old tricks when you turn it on next day. I've now given up trying, so don't waste your money on a shonky repair that wont last. A new display panel is the only sure remedy, but the cost of this would make it uneconomic to repair.

Bruce

[hamid1379]

thanks for guide. but there is some question. is bad t-com board can cause the problem? or bad gate driver ic? and there is not any flat on top of my lcd panel. these panel made with LG and have 8 flat cable only in downside of panel! thanks for guidance

[downunder]

Hi Hamid,

I have seen this fault too many times. The fact that the flat cables are at the bottom of the panel only makes things worse because the connections there may have become corroded due to liquid spillage caused by someone attempting to clean the screen.

The bonding of the flat cables is achieved by heat and glue (anisotropic bonding) and it's caused the demise of so many LCD and plasma panels in the last few years.

Bruce

[Turnip]

Hi Bruce,

Like you have tried carpet underlay over the years with only mild success on certain screens, never tried heat treatment (Read about Anisotropic Bonding on 'Wikky' as one does) wonder if a blast under pressure with the chip removal device might do the job - not yet tried, but keen, as have several underlay failures kicking about - Chris.