Rumba Issues

I recently got a RUMBA board, I was wondering if people have had issues with it,

My main problems so far:
1. Random behaviour with the endstops triggering on and off
2. Completely unable to flash Arduino with Ribbon cables for a controller attached
3. very frequent connection errors with PrintRun
4. Steppers randomly increase or decrease speed
5. Arduino seems to randomly reset during operation.

I tested all individual parts with my Ramps 1.4, replaced USB cable, ribbons etc, the issues only appear for the RUMBA board

certainly the support forums for them seem to indicate issues and there is a single blog post that I can find:[coherent-reprap.blogspot.co.uk]

At this point I am requesting a refund and giving up on it, however it's frustrating as at first appearance it is a very nice board...

I had reset problems caused by inverted endstop wiring. Check if your endstops are wired like its in your firmware defined.

Edited 1 time(s). Last edit at 12/21/2013 07:57AM by mrc.

I wish, endstops verified and correct, using Hall sensors.

hmmm weird, which power source do you use? which firmware?
Is the Jumper on Power Source maybe try if you get a stable connection with usb power?

I had nothing but issues with my rumba that is related to shoddy soldering somewhere on the board and they gave me loads of advice but did not let me exchange it even after asking 4 times. My issue was related to micro stepping spontaneously switching during a print if the board was warmed up for a while.

I was able to flash my firmware, are you hooking it up right to a second arduino?

Edited 1 time(s). Last edit at 12/22/2013 02:39PM by Coherent.

i didn´t had one problem except the endstop thing...
but i bought mine at reprap france in black, i think they are way better soldered.

[www.reprap-france.com]

I am using a modified HP server power supply, 12v up to 62 amps, very stable and showing 12.08 voltage when measured under expected load. Using Marlin firmware.
Programming the Arduino without the ribbon cables mostly works fine but even then shows random errors sometimes, no difference when powering it from USB or powering it from PSU.
@Coherent: What do you mean by hooking it up to a second arduino ?

Sorry to not be clear, I meant that you can use a second ardunio to burn a bootloader on the arduino mega.
[www.instructables.com]
This is different from simply compiling and uploading marlin to the mega. You would do this if you on suspected that the bootloader was messed up. Symptoms would be that the hardware performs erratically (huge simplification, but I think marlin issues tend to be reproducible while a corrupt boot loader might cause it to act not consistently.)