IS31FL3741rgb matrix doesn't work with m4 express 5v

[Nomsmon]

The Adafruit IS31FL3741 only seems to work (when using the stemma connector) from the metro m4 express 3.3v though the docs show (and recommend) it powered from a 5v supply.

I found this old post viewtopic.php?t=159408 that gave me the idea to try the 3.3v when the 5v didn't work.

Similar to what's described in that post, when I connect the red cable of the stemma adapter to 5v, the metro stops responding and the matrix doesn't light up.

When using the 3.3v, the metro works fine and the matrix lights up.

What's the cause of this?

I tried powering the metro from both the USB and dc inputs, but only the 3.3v works.

[adafruit2]

yah the M4 does not like the light pullups to 5V - that said it will work just fine from 3.3V power. you can use a level shifter board if you want to power from 5V and have 3V logic
https://www.adafruit.com/product/5649

[Nomsmon]

Not sure I follow. Does that mean the 5v power supply output in the metro m4 doesn't work?

Or is it related to the 3.3v logic level from the m4 in combination with the 5v power supply?

Is it generally required that the power supply and logic levels match? Or is that specific to this led matrix?

[adafruit2]

the metro m4 is picky in that the power and voltage levels MUST match and both be 3V or it doesnt boot nicely. other chips are less insistant :)