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MKS Gen 1.4 + A4988 motor only goes one way

by Keepars

Hey all. So today I finally got my MKS Gen 1.4 and started plugging away to get it working. Thermistors, fans, endstops, all that jazz expect the motors.

My current motor setups are

  • X (TMC 2100)
  • Y (TMC 2100)
  • Z (TMC 2100)
  • E0 (A4988)
  • E1 (TMC 2100) *Note E1 is configured for a dual Z setup hence the use of a TMC 2100 here

X, Y and Z1+Z2 all work perfectly and very quietly I might add so im happy. however my problem lies with E0 The motor only spins one way. I have told it to retract and extrude but it only extrudes (I am using Simplify 3Ds Control panel jog controls) in order to troubleshoot more I moved the A4988 around the other motors to find that whatever motor the A4988 is connected to will only spin one way. I have 5 A4988 which came in a kit and blew 3 of them up figuring out how they worked on my RAMPS 1.4. I also tried the other working A4988 and it is doing the same as the first one.

I know this works but for testing sake I probed the DIR pin that the A4988 is connected to and it successfully switched between 0V and 4.98V as I told the motor to move extrude and retract. However it only extruded when this pin was high and low.

I got a 4 pack of TMC2100 and tempted to get a 5th one to get away from this problem but would like to know how I can get this A4988 to work in both directions.

LCD issue solved. The problem was the lcd cable socket on the MKS GEN 1.4 was backwards.
***Also on a side note I have a LCD 12864 which does not light up. when i turn the nob I see blue LEDs flash on the MKS 1.4 indicated that something is happening but the screen is dark. I connected EXP1 on the MKS to EXP1 on the LCD, and EXP2 on the MKS to EXP2 on the LCD. for troubleshooting sake I tried to connect EXP1 to EXP2 but this didnt work. Also worth noting, the buzzer on the LCD 12864 is making a steady quiet clicking sound. The LCD works when i connect it to my RAMPS 1.4 without any problems so i know the LCD works.

Thanks all in advance.

A4988 Marlin MKS_Gen ramps reprap
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