Hi, Robert zeu Great Moderator

What's your question ??? : I have 267 Led segments on my circuit and I want to test them. But @ 20 mA each, and all together ... that draws 5.34 amps ...

OK ...

Now ... the questions

1) is it compulsory to test them all together at the same time ( and is it possible ? - some multiplexing used or not ??? )
2) you absolutely need 20 mA per segment ???

PWM won't do anything for you ... cause you have to give some energy to light on your leds - whatever the way you provide it - just to be able to see them glow.
a switching supply only could allow you to start from a higher voltage DC "mains"

From that you could understand to reduce the current draw, you could quickly test groups of leds after groups ... ( say 7 seg, then 14 seg, then leds ... i.e )
second way would be to use lower current for the test ... but that needs some scheme watching to tell if possible !

No miracle when energy speaking ... never !

Alain