It might help if we knew which marking, if any, was the date code. Are
there similar transistors, and if so, what are their markings? What
are the date codes in the ICs, if any?
Are the other components of Japanese or US origin, or somewhere else?
That might help us narrow down the manufacturer.
Is it a MOSFET or a BJT? P-channel, N-channel, NPN, PNP?
What is its function? Is it part of a power supply? Switchmode?
Linear?
It might help if we knew which marking, if any, was the date code. Are
there similar transistors, and if so, what are their markings? What
are the date codes in the ICs, if any?
Are the other components of Japanese or US origin, or somewhere else?
That might help us narrow down the manufacturer.
Is it a MOSFET or a BJT? P-channel, N-channel, NPN, PNP?
What is its function? Is it part of a power supply? Switchmode?
Linear?
Try looking up a 2SC2603, it's a fairly standard signal transistor. Due to
it's small size, they abbreviate the number to 603. Fairly common in
consumer electronics.
Try looking up a 2SC2603, it's a fairly standard signal transistor. Due to
it's small size, they abbreviate the number to 603. Fairly common in
consumer electronics.