Behringer XR18


Anyone have any experience with the XR18?

I bought a refurbished one off eBay, ironically from  Music Tribe. It had to go back for repair because channel 4 wasn't working. Received back and now my outputs seem dodgy. On bus outputs 1 + 6 seem to have a lot of noise, 2-5 just don't work?!

Channel 17+18 don't seem to work and the headphone volume seems to make everything trip out. The main outs are very noisy too. It wasn't like this before it went for repair?! 

Help ?