weird negative burnt track on lg power supply. help?

[Repair-me]

Ok so this is weird. I don't know how to explain it or why it’s happened. Anyone please help me understand this.

Lg plasma power supply. 3501v00052a.

From what I see, the track connects to the negative of the big capacitor, where I drew the black line is where it connects to underneath the board. And this track leads to a small light blue cap. The entire track is burnt. And then the solider on the small blue cap is melted. Which then connects to the ground of the TV. See I would have thought that the negative of the big capacitor and the ground of the TV would be the same? Seeing how they are both negatives and only this little light blue cap stands in the way between both but is completely damaged.

So again a total mystery, does anyone know why.


**broken link removed**

 

[Repair-me]

any ideas at all? anyone

 

[Nigel Goodwin]

High voltage surge (lightning?) and the capacitor has absorbed it, as it's intended to do - overheating the track.

 

[Repair-me]

High voltage surge (lightning?) and the capacitor has absorbed it, as it's intended to do - overheating the track.

so that shouldn't be the problem as to why it won't switch on. cause everything on the board looks fine apart from this.

 

[Sceadwian]

It may possibly still work fine, right as soon as you replace the burnt cap. Failed protection caps typically disable the device, it's what they're supposed to do, "take one for the team" Mind you the cap itself technically didn't fail, something else caused it to fail, determining that is... not particularly easy.

 

[Nigel Goodwin]

so that shouldn't be the problem as to why it won't switch on. cause everything on the board looks fine apart from this.

If it's had a surge or lightning, it would certainly explain why it won't switch on - anything could have been killed.

 

[bountyhunter]

Surge protectors have both a maximum energy rating as well as a clamping impedance. In other words: they only handle a certain amount of energy. If they take enough to destroy the clamping device, that means it blew into an OPEN circuit which would mean the clamping action ceased and the protection was gone. If you see burn damage, I would tend to think other things might hve been injured. Maybe not, but IMHO it's likely.

 

[Sceadwian]

And just because that's the only burnt trace doesn't mean that's the only non-functioning component.

 

[Repair-me]

i found the fault.. x drive is short. so any 200v vs going to the x drive shorts out the psu. and it looks like i need a new x drive as it doesn't have much components to replace other than the main x drive transistor which is unique to this plasma. . which i can't find no where. ah well. it had to die someday.