martin mac 250 krypton

I presume you are talking about the display on the fixture itself?

If so, a post on the Martin forums might get you a quicker response, or even better, a call to Martin tech support...

I can't remember if there is a setting on the 250's to have the display timeout after a while or not - does it come to life if you press a button? Does the fixture calibrate when you power it up? Are there any other signs of life on the fixture?

That's where I would start troubleshooting anyway.

Yea  . I'm gonna post on martin forum . but yes it does calibrate. But the display won't show anything . thks