Ramps 1.4 damaged by measuring with multimeter?! (1 reply)

hey guys.

I am on my second 3D printer - a prusa i3 which i am quite happy with.

since i have been experiencing some Y-axis shift in longer prints lately i wanted to measure for a little bit higher V-Ref on the trim poti.

I therefore set the positive side of my multimeter on top of the poti and the negative gauge on to the (supposedly) gnd pin.

Accidentally i mixed up the potis on my 4988 Drivers from Gadget 3D - which have two trim potis on each driver, one for Vref, one for Decay.

So i "measured" between Decay (ROSC) poti and UMDT instead of ground.

Here a picture of my driver:

[reprap.org]

Instantly when touching the pin with the measuring device, I heard the unplugging sound from Windows - same as when you unplug your USB Stick.

now only the middle green LED keeps flashing and my PC will not recognize the board anymore :-(


What could i potentially have damaged?

Maybe killed the bootloader? need to reflash the board in the best case scenario?

I do have an AVR Programmer here so i would be able to flash a bootloader on there if i can get the board to respond via miso/mosi etc. pins.


I just feel like i might have fried more :(

Alex.