Cant set 1/8 stepping - DRV8825

Hi recently I bought a second Ramps 1.6 (ramps 1.4 with mosfets and stuff) to have a spare and oh boy did I bought it right in time. My last board (same as the new one) shorted out while trying to figure out the vref on DRV8825 drivers.

I changed the board, drivers (it fried two of my TMC2130 drivers), cables all just not the extruder motor. On this new board I cant get 1/8 stepping and idk why. I checked the board for solders and it looks OK. I removed the MS3 jumper, even tried different jumpers but it seems like I still get some incorrect stepping.

Previously, before shorting out the first board my settings were: 1/8 stepping, 1900 steps and it worked perfectly.

Now i get horrible under extrusion which seems to be the problem of wrongly used microsteps. I have set the stepping to 1/4 and 1900 steps and it still underextrudes by about 10-15%.

Can anybody tell me what the hell is going on ? Both of the boards are clones ...

Some of the cheap ramps boards have pcb tracks between the micro stepping jumpers, so they are always connected

remove the driver module and the jumper and test with a multi meter that there is no connection between the two jumper pins

PS Dont use metal screw drivers when adjusting vref, use a shaved tooth pick if you don't have plastic or ceramic screw drivers

Edited 2 time(s). Last edit at 10/12/2018 05:13AM by Dust.

I used to use a single LiPo battery to shortcut and melt away these damn bridges.