Welcome to the SeeMeCNC Community

Hey,

I have a RMax v3 kit

Today I fired up my printer for the first time in about a month, and was going to start using it again. It took "forever" to heat up before printing. (like 20+ minutes) then went it got to the designated temperature 210 noz/60 base the lcd read out simply said "def" for both temperatures and started to cool down. I tried to use it again after resetting and letting cold down, but it started to smell pretty bad, and I turned it off and picked up the Onyx heating bed and started to look, for what went wrong. After looking for a moment, I noticed smoke coming from the fan holes on the power supply.

I tried checking the top of the unit and the heating bed for any signs of a short that could do that, and I didn't see anything "obvious".

I assume I'll be ordering a new power supply at the least. But I could really use some help tracking down or testing to make sure I don't blow it out when I plug that in. Where should I start?

Thanks much.

I would check for any bridged connections, and check the resistance from the power supply terminals. If any are under 300 ohms when off, you may have a problem. Any under 1 ohm when off are a smoking gun.