Scratch on logic board. Any fix?
There is a scratch on the logic board that I think this is why the display is black is the anyway to fix the scratch
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@superfixer334 only by gently (using a scalpel; or similar tool) and carefully scraping the masking of the trace. Once the copper is exposed (careful those are all thin layers) solder a piece of wire across the severed trace, reconnecting both ends. Then cover the jumper with a non-conductive paint. It's tedious and requires some practice but can be done.
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When the break in the trace is very short, I've worked with some really good technicians who would bridge the break with conductive paint then coat it over to seal it. These breaks look like they would be pretty short, so it might even be possible to bridge them with just solder if the ends of the traces are close enough together.
@dadibrokeit correct they even make Bare Conductive Electric Paint Pen for that purpose. It's just I never had much luck with it and prefer the soldering. CircuitWriter was a big brand for those pens.
Bridging with solder is possible on a wider break if you lay copper filings between to give the solder a path. Flux needed. They also make peel-off traces on sheets but I've never used them. these technique's alsowork on flexible film connectors. @oldturkey03 is right, tedious. A microscope would help, but I've done both board's and film with just a magnifying glass. Drag soldering can let you do multiple breaks at once, seen it done but can't do it myself, probably because my iron is crap. LOL. Id practice the techniques on something else first, also the copper filings trick works better with paste solder.
@dadibrokeit - The signal type and the lines length become a concern when using conductive paint.
A simple digital signal state change within a short distance it works just fine! Signals that need to travel longer tend to lose their edge from the added resistance and if the signal is not buffered.
High current signals tend not to hold up as the paint breaks down (resistance). So a backlight power line or a speaker audio signal for example would be to risky.
The paint is a great EMI/RF blocker (the microwave range being the exception if the coating is thin)
If the cut is not to wide a simple blob of solder will do. If more an a cut I would put down a thin piece of wire as well.
@danj - Looking at the overall picture, I'm guessing the broken traces are part of a set of differential pairs, which would make sense if it's part of the video signals. But differential pairs implies the need for high signal integrity, which argues for a solder/wire approach rather than conductive paint.
