Help Needed - New Build: Power Issues Part 1

[beilmandesign]

Hi guys,
My (mechanical) build of the MAX went well with no issues. Powered up and proceeded thru the instructions.

Stuck with one isuue: with one or both sets of red & black heater wires screwed into the Rambo I cannot adjust its temp settings without a shutdown both rambo & P/S.

The x, y & z axis end stops were reporting h's when queried with the the M119 command. I checked everything until I found that the pins in the connectors on the rambo board were not making contact. No amount of force, wiggling, or jiggling could make it work. In my 1st attached picture below you will see that I removed the pins from the plug in connections and inserted them directly into the female socket. This caused all axis to report L's as needed.

bare pins inserted in the rambo end stop locations

The thermistors both were reporting ~23C, but when I tried to turn the heat up (or on) the control panel shut down. This was true if I did it on the max lcd panel or thru Mattercontrol. The bed heat led will not come on. I pulled the bed and there were no wiring issues, bridges, shorts, or broken connections. I checked all the plug in & screw in connections on the rambo board but the issue persists. Again this issue is true of both the hot end and bed heat. All fuses were checked several times and are good to go. Again, no amount of force, wiggling, or jiggling could make these connections work.

thermistor connectors

So is my p/s supplied with the kit underpowered?
Thanks in advance!

[Earthbound]

You should leave the thermistor connectors alone. There is nothing wrong with them. We know this because the LCD screen is showing ambient temperature values meaning that it is reading the thermistors properly.

What do you mean by "the control panel shut down"? If the backlight is shutting off then power is cutting out, possibly from a short in the heater circuit. Might be best to start with hot end and heated bed disconnected from the RAMBo. If the LCD panel stays on then, you've isolated part of the problem.

Do not rely on the hot end LED to be the sole indicator of hot end function. LED could be bad, mis-wired, or installed backwards.

[beilmandesign]

Ok - if I have both sets of heat wires pulled out of the screw terminal I can adjust the bed or extruder temp on the lcd panel and the lcd does not go blank (and the rambo does not shuts down either). If I have either one or both sets of red & black wires screwed in I cannot adjust its temp settings without a shutdown.

[beilmandesign]

Bed heat Led is installed correctly. Measured bed resistance at 1 ohm.

[jckrieger]

Check the 12V output on your power supply. You can easily check this with a multimeter on the input of the rambo board. I'm guessing you're going to read less than 11.7 V, and it drops to zero when the power goes out. I'm guessing you have a bad power supply (I went through the same thing with my recent build). My supply was making a screaming sound with the heaters on, so that's one dead giveaway that something is awry.

[beilmandesign]

I have purchased and installed a Corsair CX750M power supply. It worked like a champ to power my machine and all heats come up rapidly. I highly recommend something of this size & quality for all new Max 2 kit builders.
http://www.corsair.com/en-gb/cx-series- ... odular-psu

[lightninjay]

That's actually the exact power supply I purchased to replace my burnt up one, and I picked it up from Bestbuy in a pinch.

I chose to hack on old ATX connector off a recycled motherboard that had died, and used that to jumper my ATX connector to the power switch, rather than voiding the warranty of the supply unit by cutting and breaking out the green and a black wire.

This also allowed for me to only chop one of the modular cables, and keep the power supply in warranty state

They make adapters so you don't have to do what I did, but I was pressed for time and wanted my printer up and running lol.