Selphy CP1200 prints having streaks and artefacts on them

My pictures are coming out with lines across the left hand side, as you can see from the picture below.I have tried the following:

1)different size paper

2)different ink cartridge

3)visual inspection

How can I fix this?

Can I do it myself?

(PS: I bought the printer 2 months ago in Japan, and I live in South Africa. The local agent here says the warranty is not valid)