Ramps 1.4 / smart controller / repetier host

I've just finished my first printer and everything seems to be working lik it should. This is my setup:
- Mendelmax 1.5
- Ramps 1.4
- reprapdiscount smart lcd controller
- repetier / repetier host.

The thing is: it seems that whenever I've got the lcd connected to the Ramps, I can't control the printer with my computer (it says the com port isn't detected) I'm thinking that is has to do with the lcd already being connected and thus "blocking" the computer. My problem is that I would like to put all of my electronics in a console, which means that I won't be able to disconnect the lcd. Does anybody know if this is indeed the case and if so, of there is a workaround for it?

I cant help solve this, but i have a Ramps 1.4 and reprapdiscount smart lcd controller using marlin firmware and I am able to control over usb with the screen plugged in.

So maybe try marlin. If it still doesnt work it might be a hardware fault.

Sorry I cant help more.

I also cant help solve this, but I have Ramps 1.4 and a custom LCD panel using Repetier firmware, and I am able to control over usb with the screen plugged in.

So combining that with lazzymonks setup, your setup should technically work.

Does reprapdiscount have a preconfigured firmware image that you could try to rule out a hardware issue?

I don't know what I did wrong, but it's working for me now.
Have already built everything into the console. Just waiting for my 24V power supply for my heated bed now.
Thanks for trying to help!

Quick follow up question.
Did the firmware work with the LCD out of the box for did you have to do a lot of the changes described on the Repetier site?