I have a very odd problem

A few months ago, I had to replace my Ramps 1.4 board - I melted the electronics from a poor connection to the heat bed.

I replaced the Ramps 1.4 board and got ArduinoMega just in case it also got damaged. With the new hardware, I reflashed an old sprinter firmware that I have been using for two years without fail. The issue is the motors have gone screwy. They will jump in big steps or just hum in place. The steppers seem fine though: I can run this test code just fine. I added a new stepper and new motor anyway, it is exhibiting the same problem
Stepper pots are tuned nicely to ~0.41 V, they turn no problem with the test code - nice and smooth

Tried two USB cables - same problem

Installed Retpetier-Host and it exhibits the same behaviour. Tried Marlin firmware, getting the same issues.

If I turn the steps/mm way down in the firmware the motors do better (from 100 steps to 15), but still act strangely. I'm essentially getting no smooth movement, really jerky action on all the motors, or inconsistent number of steps, or it just sits there and buzzes.

Heat bed, hot end, end-stops all working fine. Any suggestions? Could my power supply be causing this?

Did you forget to put the jumpers for microstepping under the drivers?

What version of marlin are you using ?

O_Lampe - Not sure what you mean about the jumpers. I didn't require jumpers before, at least I don't think I did.

Obewan - Marlin 1.0.2-2

Still haven't gotten anywhere with this... I'm pretty much out of ideas :/

Quote
elkell
O_Lampe - Not sure what you mean about the jumpers. I didn't require jumpers before, at least I don't think I did.

Some of the chinese ramps boards had traces underneath where the 3 jumpers would normally sit, some of the chinese ones don't. The only way to find out is to lift up the black plastic on the base of the jumper pin to see the trace on the top side of the board or check it with a multimeter.



You might need to check your old ramps board and/or the new one to determine if you have these jumpers installed or not.

Solved --> o_lampe was right. The new Ramps board I bought did not have any jumpers under the stepper drivers. I didn't realize this because my first ramps board came with them pre-installed. I feel pretty dumb right now but glad that it is fixed. Thanks a million o_lampe

If anyone else experiences this, I feel your pain. The picture shows where the jumpers go.