samsung un55hu8550f dead,

[milleradam37]

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

[budm]

Re: samsung un55hu8550f dead,

You will get a lot more help if you upload good clear pictures of the whole backside of the TV showing all the boards so we can see what we are dealing with.

[Unspun01]

Re: samsung un55hu8550f dead,

If you are interested in component level repair, place your multimeter in continuity/diode mode. Touch leads together. Does it beep? Good.

Now place leads across the +/- of each surface mount capacitor. Measure any persistent shorts? These caps are connected to power rails and may highlight problems on a specific voltage rail.

Also with black lead on chassis ground, touch any lead of all surface mounted coils. There are many on your board labelled 3R3 or 1R0 or 1R5 or 4R7. These coils are connected to power rails, and any short circuit to ground on these components will highlight a possible problem with a voltage rail.

Note that these components themselves are rarely the issue, but likely a transistor or IC connected on that power rail.

Another thing you can do is to use a hot air dryer to heat the large heat sinks or other BGA ICs and then plug in and power on.

If you find no shorts, and heating the board for a few minutes doesn't allow TV to show any sign of life, then you will need to start pulling datasheets of marked ICs and see if there are other shorts from VCC to ground, etc.