RUMBA - plugged in motor driver the wrong way, now windows doesnt notice USB connection

Hi, i´ve got a problem with my RUMBA and i hope you guys know what i can do to get it back to work. I cant connect to my Computer with USB. It just doesnt get recognized by Widows 7 64bit.

It worked for several weeks with the Stepsticks (A4988) that came with it. However i was going to switch to DRV8825 Stepsticks to try and see if they run cooler than the original ones. Unfortunately i did not pay attention to the writings on the back side and plugged one in the wrong way. It took about 5 seconds after powering on and something on the stepstick went up in smoke. I eyeballed the RUMBA but i cant see any damage. I might mention that the Board was powered by a PSU with 24V at the time this happened.

tried several things to get it back to work, including
- un- / installed everything Arduino related (Arduino IDE, RRD_RUMBA_TAURINO_Driver from Arduino Website)
- un- / installed the com port (and the FTDI Drivers) that was used by the Printer
- complete whipe and fresh windows install
but nothing was successful. The Board doesnt get recognized by a Laptop that is also on WIN7 64bit either.

I dont know what to do anymore, can you help me?

best regards
stacker

EDIT: removed typo

Edited 1 time(s). Last edit at 01/29/2015 03:00PM by stacker_fb.

Have you removed all the stepsticks and tried to see if the board connects with nothing plugged in? If you're lucky, you just cooked your driver(s). If you're unlucky, you may have fried one of the voltage regulators or one of the microcontrollers. A bit of probing on the 5V and 12V headers between the microcontroller chips might reveal if the regulators are working correctly. Also disconnecting external power and moving the jumper to USB powered will take the regulators out of the loop.

Hi, thank you for your fast reply!

I just removed all stepsticks, endstop-, thermistor- and motor Connectors and jumpered to USB Mode, still no connection. I dont have a multimeter so i´m kind of restricted to plugging things in and out. :-/