hello all i have a samsung un55hu8550f, with a main board that has bn41-02205b as part number? anyway, the unit is dead if i disconnect the powersupply board from the main brd then the backlights do come on, i tried to plug back into main brd and disconnect other connectors one at a time to isolate problem, i pretty sure the main brd is bad, just wondering if anyone knows a component level fix for this brd looks like a used one is $150, which will make this a very unprofitable repair, any help appreciated,

thanks

Re: lg 55ls4500 negative picture

Ok, so i finally got back to this 'dog' , and have successfully repaired the corroded traces and components, not pretty, but it worked! thanks for all of your input guys. i drew some of the corroded part in case anyone else needs in future. also, maybe for future reference check to see if the following are open when brightness doesnt work properly r215(smd 188 ), r216(smd 472) , r210 (smd 272) , r213, r214(smd 101) r211,r212 (smd 08A (eia-96)). c251, c250 had corrosion as well, but i couldnt find any numbers and could get a reading only about 100nf,...

Re: lg 55ls4500 negative picture



i was actually hoping someone here might by chance have one of these units and could ohm them out, when i checked them after cleaning them up i got nothing. i tried looking on the other board to see if the same resistors were there, but apparently the boards are different (l) and (r) marked on each. the damage was on the left board. i tried to find these boards for sale somewhere, but nothing yet, considering that a cracked panel would make these boards worthless unless you have some water damage like this that is still possible to...

Re: lg 55ls4500 negative picture

ok, found original problem== i feel pretty silly now for not looking here before, looks like along with the water damage i have corroded traces and smd resistors. i dont suppose anyone knows the values? i can make out a couple but the rest i cant make out. also has any successfully repaired similar ? i doubt i will attempt to replace the board dont have a good way to re-attach those ribbons...

Re: lg 55ls4500 negative picture

ok thanks guys i will double check the part number on board, i ordered the new one from shopjimmy supposed to be a good place. so, is there a chart of gamma voltages anywhere? will those voltages change as you adjust brightness? is the brightness pwm or linear controlled?

Re: lg 55ls4500 negative picture

ok, after a little research it looks like the actual problem is called solarization.... the menu always appears normal so i am fairly confident that the panel is fine, but the fix is supposed to be either main or t-con board, both of which i have already changed. im thinking that i received a bad main board, thoughts? does anyone know of anything on the main board that is replaceable for this issue? i really dont want to invest any more money into this than i have to at this point

Hello all,

i have an lg 55ls4500 that appears to have a brightness problem, when i turn the brightness up past 75, i have a decent picture, but when set on 50, which is supposed to be standard setting, i start getting a negative picture which gradually gets worse as the brightness decreases.
When i first got it, the image from other input would stay on screen forever, so i changed the main board, which seemed to help, but still had the negative image in the picture here and there , had to reall play with adjustments to get a decent picture. So now i changed the t-con board...

Re: LG 55LS4500 - T-Con or Panel?

hello, for some reason i cant start a new thread, but i have lg 55ls4500 that has a picture, but sometimes with various colors flaring out from edges. i can adjust the flares out using advanced settings, but when you select a preset adjustment such as 'movie' , the flare outs come back. tried all inputs and doesnt seem to matter. when i first got the set you could see an image in background from a different input(ex hdmi input is faded in background when switching to av input).
thinking it had to be the main board i replaced it, which seemed...

Re: New Members - please post your introductions here

hello, my name is adam been fixing electronics since the 80's , but still get stuck from time to time on a dog....