Power Supply / LCD Screen Issue

I've been running my 1st generation gMax 3D printer for almost a year and a half now and have had minor problems off and on, but nothing huge.

A few weeks ago the printer started shutting off intermittently and then sometimes turning back on and other times not until at last it would not turn on anymore.

I figured it was the power supply so I sent it back to the manufacturer and received a new one. I also switched out the RAMPS 1.4 board with a new one as well. That all being said, the board lights up and the LCD screen glows now, but there is no text. If I hook it up to the computer with a USB text shows. However, I cannot control or engage the motors to move. I'm currently at a loss.

Any thoughts would be greatly appreciated. I'm not sure if the 12v isn't engaging somewhere or what...

You mentioned that the LCD screen does come on when your connected to USB. But you do not have control of the printer. Can you control the printer through a host program like pronterface? This is quite strange and I hope we figure it out.

We have a troubleshooting discussion on this.


Would you mind moving the discussion to this thread? I sent you a PM.
After more trouble shooting, I bought a new ramps board, and rewired the whole thing. It is now running, but my steppers are no longer calibrated correctly so I will need to go back in and re-tune them :(

I came to the conclusion that everything was running through the 5V (low voltage) fine, but there was no power to the motors. I couldn't run through my computer program either.

Frustrating, but we seem to be moving towards a solution. My only question now is if the amperage to the board matters?

The Ramps calls for 12v 5amp and 12v 11amp and my PSU uses 12v 34amps
If the PSU is rated for 34 amps at 12V, than 34 amps is the maximum current the power supply can output. Which is quite a lot of current. It is perfectly OK that the printer does not draw this much.

Did you check that the power button is working correctly?


New Member
We are also having this issue. Screen worked fine yesterday then we moved the printer across the office and now the screen is only dimly lit with no text visible on the screen. We have checked to make sure the correct cables are plugged into their corresponding ports and the connections seem to be fully connected.

Any suggestions?

sorry this is posted to the wrong thread, but for some reason I keep getting logged out and get post it where I originally intended