My Makerfarm Prusa i3v 8" build

[eghm]

A injury slowed down the build, but finally managed to get everything together. Finished up the wiring tonight, but it seem like RAMPS is getting no power? I've got a magma head so the fan is wired directly into the ramps power connection. That works, but that is it, no LEDs, no LCD. I've checked the power connections multiple times as well as taking it apart a few for kicks. Any advice would be appreciated. Thanks!

[gmay3]

Hi eghm,

What type of power supply are you using? If you are using the ATX PC type power supply, usually you have so connect two logic wires together to get the supply to allow current to flow through the 12VDC lines, but consult your power supply manual.

[TopJimmyCooks]

He's got 12V because his magma cooling fan is working. eghm, remember you need to connect 12v + and - to both the 11A and 5A sections on the ramps board power plug. Also, does your ramps board and lcd light up when you plug in a usb cable to the pc? if that doesn't work there may be something defective. Check those and if no luck post a pic of your ramps connections.

[eghm]

Thanks gmay3, ya I've got the connection made on the ATX, i've used an ATX as a power supply before so was expecting to need to do so.

Yes, TopJimmyCooks, I've got 11A and 5A wired up as described ( I'll attach a picture later). No LCD or LED lights when I plug in my usb cable to either of my Macs, I do get a "USB Device is drawing too much power" warning, and the ramps board does not show up on my list of USB devices.

[gmay3]

Have you tried unplugging the 11A/5A connector, fans, and other peripherals from the RAMPS board and then plugging in the USB? I'm guessing that there is a short somewhere since your computer is saying it's drawing too much power. If you can rule out the add-on wiring then that would be proof of a defective RAMPS board which I would think Colin would replace.

Be careful though, it's not worth damaging your computers USB port or getting a shock over to try to debug it too far!

[eghm]

DSC05618.jpg pic of my wired power plug as requested.

[printbus]

The fact that the computer is detecting a USB power problem indicates to me that there's a problem in the 5V distribution somewhere. I don't think that would pick up an issue in the printer's 12V wiring. A problem in the 5V would have to be in the USB cable, the Arduino/RAMPS board pair, or the smart panel. If I understand the Arduino power select circuit, a shorted USB cable would be an issue for the computer but the Arduino would still power up from the printer's power supply. That would leave either the Arduino/RAMPS or the smart panel as primary suspects, but I'd still try another USB cable if you haven't already. Definitely try unplugging the cables going to the LCD and see if the error on the computer goes away when attempting to power RAMPS from the USB cable. As another power indicator to watch for, I get two short bursts of green on RAMPS LED1 when the Arduino/RAMPS pair powers up.

[eghm]

Disconnected the stops, steppers, and therms then I get the 2 green LED flashes and the LCD displays and the USB device power warning goes away. Looks like there must be a short in one of those, I'll plug them in one at a time and see if I can track that down. Thanks everyone for your assistance

[printbus]

Disconnected the stops, steppers, and therms then I get the 2 green LED flashes and the LCD displays and the USB device power warning goes away. Looks like there must be a short in one of those, I'll plug them in one at a time and see if I can track that down. Thanks everyone for your assistance

Oh, yeah, could be a problem in the endstop wiring too. Double check which two of the three pins you're using in the 3-pin endstop connectors. You might have the endstop switches incorrectly wired between +5 and ground. That would not be good.

EDIT: Looking at the RAMPS board mounted on the printer, the endstop switches go to the two pins on the left side of the 3-pin connectors. If they are installed off a pin to the right or the connectors are installed rotated 180-degrees, the endstop switches will be wired between +5 and ground. The motor and thermistor wiring wouldn't be a factor here since neither tie directly to the 5v distribution.

[eghm]

Oh, yeah, could be a problem in the endstop wiring too. Double check which two of the three pins you're using in the 3-pin endstop connectors. You might have the endstop switches incorrectly wired between +5 and ground. That would not be good.

EDIT: Looking at the RAMPS board mounted on the printer, the endstop switches go to the two pins on the left side of the 3-pin connectors.

I suspect this might have been the case, having plugged everything back in everything seems A-OK now.