trouble with my sp300v

Im having trouble with my roland sp-300v.It seams that I can not get the magenta and yellow to print. I have replaced the print caps, dampers, cleaned a bunch, and even tried to pull ink through manually and nothing. I was told it was a print head, a fuse, or a pump could be bad. Any ideas on what to try or do next, this thing is going to get me a divorce if I dont get it working soon I think. I would like any help I could get. Thanks