RUMBA board- how to do complete setup, including firmware and wiring? (Page 6 of 10)

Yes, hook your negative probe onto the ground input for the board.  Positive probe goes on the rim of the trim pot.  My best guess for your beeping issues is still the VREFs, get those tuned to where they need to be and it will probably go away.  Try to tune it to the voltages that I posted for the drivers you have.  If it still makes slight noises, that is probably okay.  You must fine a "good enough" balance between noise, temperature, and enough power to avoid skipping.  Getting all 3 of those perfect is unlikely but you should be able to get close.

You can power it separately (preferred) or jump from Main PWR to HB PWR.
It just depends on your setup.  I have set them up every way so if you need help let me know.

That's actually a picture of my PSU
Do you have a supernight PSU?

Because the 3 banks aren't internally connected I jumped them all together to get 360 watts.
If your setup is what I am thinking you will want to connect MAIN PWR to one bank (120 watts) which is plenty to run the motors and hot end.  Then you will want to connect the remaining 2 banks (jumpered together like above photo) to the HB PWR terminals.  This setup will give you 240 watts dedicated to the bed heater only.  Of course this means you will have another set of power wires going to your board. 
Does that make sense?

I made the same assumption and they actually test as if they are connected.  However, the current capability just isn't there unless jumped.

Based on my testing the answer given is correct, sort of.  I am guessing the traces on the circuit board that tie them together are simply too small to deliver the full current.  I haven't had one apart to verify this but can say connecting them together eliminated any and all signs of low current (LED flicker & fan speed changes).  Wire it up any way you want if connected to just one terminal doesn't deliver, add the jumpers.  You won't hurt anything.

Same control as before just a designated circuit for a separate PSU for the bed heater.

You can either make new connectors or just cut the wires and use the screw terminals.
The extra header is just that "extra" so us it for what ever you want.

It is getting late but rest assured your board is fine   I will be happy to help you in the AM.

Well for now I'd try reinstalling rumba USB driver, and maybe try a different USB port. It does sound like a driver issue more than a board-fry issue!

Also make sure nothing that might steal the com port is running (e.g. Repetier).

I did reinstall the drivers and tried several usb ports and cables, same result. Also disconnected everything but main power and usb. I had most of the connections hooked up when this happened so I may have shorted something. Could have hooked it up wrong , I really can't show you now.It's not a usb issue as my old sang board is still recognized. Back to the drawing board.