Get out the 40x binocular microscope and search for that chip part that
isn't soldered at both ends. Its probably near the key jack. When you
find the loose part, get out your microtip soldering iron and solder it
fast (using 2% silver bearing solder so you don't leach the tinning off
the chip). It could as easily be a chip resistor, capacitor, or lead to
an IC.
Otherwise you have to find some voltage you can get a meter or scope
probe on and chase down the circuits feeding that to find where the
intermittent open is. Then will still need the microscope and microtip
soldering iron to fix it.
73, Jerry, K0CQ
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