Z-Axis moving only one direction

I just updated my ramps 1.4 to 1.6 for my arduino mega 2560 ,because the heatbed N-Mosfet has burned up and everything is working except one thing, i cant figure out why my Z axis dont wanna move up, even if i tell from uart to move u it allways moves in the same direction.
Here is a couple of things i did to debugg the problem.
1) Switched the A4988 stepper driver from Y axis, result : Didn't change anything the problem persisted in Z axis, so the A4988 is Ok.
2) Switched the ramps 1.6 to the old one (still working but no bed control), result : Everey axis works as expected.
3) Meassure dir pin in Z-axis stepper motor (with ramps 1.6) , result : The value changes from 4.9 to 4.7v .
4) Meassure dir pin in Y-axis stepper motor for comparisson (with ramps 1.6) , result : The value changes from 4.9 to 0.1v .

So, the problem relies in the ramps, but i wanna know if anyone had even a similar issue bcz the controller is brand new and everething else it's working fine, its just rare ...

Thanks in advance , and srry for my english.

Turns out it was a bad soldered dir pin on ramps. Resoldered it and it works like a charm now.

Edited 1 time(s). Last edit at 07/02/2021 03:25AM by nadaol.

I had a controller that had an open trace in the photo below (wish It was of better quality)



I searched visually and could not find the problem, the firmware was working a another 3D Printer.
After doing a continuity test found that that the trace was open visually could not see the open trace until removing the silk screen.

simply soldered a bridge over the bad trace and the controller works.

---

Computer Programmer / Electronics Technician