Ramps 1.4 - Multiple problems

Hello,

I have a Ramps 1.4 board and I have flashed it with Marlin 1.1.8 in EFB config, and I experience multiple problems:

- The heatbed is always on, as soon as the power is turned on the heatbed will start up heating. The heatbed is connected to D8

- The fan is not spinning up when the power is turned on (not the fan connected to D9, but the one near the X axis stepper). The fan spins if I connect it directly to the 12v

I'm inexperienced with the Ramps board, so I don't know where to look/how to debug further. It could also be that the board is damaged somehow, but I want to make sure that the FW is configured properly and the connections are OK before ordering a new one

Quote
thastealth
- The heatbed is always on, as soon as the power is turned on the heatbed will start up heating. The heatbed is connected to D8

Make sure that the tabs on the MOSFETs are not touching - I've seen this problem on some RAMPS boards.

Quote
thastealth
- The fan is not spinning up when the power is turned on (not the fan connected to D9, but the one near the X axis stepper). The fan spins if I connect it directly to the 12v

Are you sure the polarity is correct?

A close inspection for solder shortcuts or cold solder joints is the first thing everyone should do, when buying cheap electronics.

Edited 1 time(s). Last edit at 05/18/2018 02:12AM by o_lampe.