I used to have an sc500 and that doesn't look great. Get in touch with Roland. I'm based in Sydney, and I find their tech support to be excellent. I see you're in Victoria, so there might be a different office in Melbourne you could ring. They only have a small team and sometimes you have to wait, but they are worth the wait.
Send the image to
support@rolanddg.com.au
You could try a manual head clean, but to me, that looks like a serious problem, possibly a new print head is needed, thats going to be $1k - $2k.
It's an old machine, so a new head is possible. You need to consider if you can justify the expense. From my experience that machine is a work horse, for solid colours it is fine. Newer machines are faster and have a wider gamut, but I find solid colours are where it is at for signage.
Since the machine is old, and likely out of warranty you should consider using a bulk ink system. A lot of people swear by them, and you've got no warranty to lose. I don't use them myself because I have a new machine, and a warranty to maintain. Search on this site for the ink systems, you'll find some info. Third party bulk ink is a lot cheaper to run.