Any electronics whizzes recognise an axial diode slightly smaller than a
1N4001 bearing just the marking "4L" along with a blue cathode band? It's used in a switch mode power supply of 1993 vintage running at around 25kHz. No other clues I'm afraid.AWEM
If you can say where it's used (input rectifier, output rectifier, etc) and the rating spec of the SMPSU, we can almost certainly give you a current part number to use as a replacement.
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