Would be helpful to know what laser you have. Also, I hope you didn't look straight down into it to see this red glow. If you saw red, it's not IR filtered. and you can't really see IR much at all yet DPSS lasers output it usually in non-eyesafe amounts and in a reasonably low divergence beam. Just because you can't see it, doesn't mean it's not frying your retina.
Just hazarding a guess, and since you said it still put out some green, I think the driver died and it's not putting out enough IR to drive the crystals (which, if you looked down the bore, is a good thing for your eyeballs)
That or you have a bad connection somewhere.