Welcome to the SeeMeCNC Community

I built my kit about 2 weeks ago, and for the most part, it's awesome.

But lately, about 20% of the time that I manually heat the hot end and bed, a few minutes later the power will trip and the whole machine will shut off. Then I have to turn the the power switch off and back on for it to power back on. I know I’m not the first to have this problem. And this has only happened a few times during an actual print. Mostly it happens when I manually heat them together. Then sometimes the trip will be caused by manually running the extruder after the hot end and bed are already heated. So It’s obviously happening from an overload of power.

I have checked the wiring going into the power connector in the rambo, and all seems secure. And again, this is a semi-infrequent occurrence. I have run several 10 hour prints without problems. But it still happens every now and then. How can I trouble shoot the cause of this issue?

I have been told by a Max v2 owner who’s an electrical engineer to possibly bundle 1 addition matching PSU wire to each of the 4 single wires that are inserted into the rambo power connector. I am electronically challenged, and i wanted to see if this is something that others would recommend before I tried it.

Could someone tell me exactly what is being powered by each of the six connections on the rambo power connector ( the 2 bundles of 4 wires and the 4 singles)

Also what would be the best process for checking the voltage drop on the PSU and rambo power connector? (remember I'm electrically challenged) I just want to figure out how to diagnose these overloads. Much appreciated!!!

Are you sure it's not that your PSU is overheating? I'd try taking the panels off your base to increase airflow and see if you still get the same shutoff issue.

BenTheRighteous wrote:Are you sure it's not that your PSU is overheating? I'd try taking the panels off your base to increase airflow and see if you still get the same shutoff issue.

Are we talking the melamine panels or the acrylic ones?? And if that was the case, why didnt it overheat during any of my 10 hour successful prints?? Thanks!!

The power supply is overheating. When you are printing, the heating elements are being modulated to maintain target temperatures. When you manually activate the heaters, they are running at full power draw until they near the target temp. At the start of a print, the hot bed gets heated first, then modulates while the hot end is warming up.

Test the overheating theory by removing the rear plexi panel and the two side melamine panels. If it helps, you can then print a vented version of these panels as a replacement and perhaps add a fan. If removing the covers makes no difference, then your machine is suffering from CPSS (crappy power supply syndrome).

Earthbound wrote:The power supply is overheating. When you are printing, the heating elements are being modulated to maintain target temperatures. When you manually activate the heaters, they are running at full power draw until they near the target temp. At the start of a print, the hot bed gets heated first, then modulates while the hot end is warming up.

Test the overheating theory by removing the rear plexi panel and the two side melamine panels. If it helps, you can then print a vented version of these panels as a replacement and perhaps add a fan. If removing the covers makes no difference, then your machine is suffering from CPSS (crappy power supply syndrome).

Thanks for the great explanation, will definitely try this and let you know! for the printed side panels, would the fans be wired to an extra yellow and black from the PSU? I'm a designer not an engineer, and I'm embarrassingly new and uncomfortable when it comes to electric wiring!!

For 12VDC fans yes.