The safest way is to try and determine from schematics
what trace is cut and what chips the trace connects.
Then solder a replacement stitch wire to the legs of the
chips originally connected by the trace. I have shematics
and can try an help identify the broken trace. Another way
that takes more experience is to use an exacto blade
(or similar) to carefully scrape away the insulation at
the two ends of the broken trace, then solder a tiny wire
bridge across the break. A small iron tip is needed for this repair.
Scrape the insulation, "tin" the bare trace with a micro-TINY
amount of solder, hold the tiny wire bridge in place
with tweasers or pliers and touch the solder iron to the
wire bridge. If there was enough solder tined on the trace,
the bridge should solder into place and you're done.
For any skeptics, I've been using these same methods for
15 years to repair hundreds of boards of every kind.
Works like a charm, and the repair is usually invisible to
the average user.
Good Luck
Plaz
