[Chaos84Camaro]

I am selling a Zero DAC that has some biasing problems over all usage (To the left). I'm curious if I'm able to fix it or if someone could find something wrong with my unit. I took some photos of the internals and it looks to me that unit has been modified in some ways (base don stock photos). Tell me if there is anything strange in your opinion. 
 
http://s285.photobucket.com/albums/ll70/Nfchaos2003/Zero%20DAC/