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My cheat sheet shows the K1G is an NPN transistor #MMSTA05 for which a MMSTA55 can be substituted. Measure the package and pin spacing. It comes in SOT23 and SOT323 packages. It is rated at 60V and o.5 A,
If your package is not one of those, then that ID might be wrong, as they often can be when based only on the SMD code.
EDIT: My other source doesn't show a K1G, but for the 1G it shows a BC847C with a BC547C as a substitute. Case is a SOT416. Check your measurements.