Zenit 12XP - blue horizontal stripes

Hi Guys,

My problem are blue horizontal stripes comin up on photos ocasionally.. or ever comin up on the majority of the photos. It's my first film made with Zenit 12XP and I am kind of disappointed. Please see the attachments and kindly advise:

Bad light:


Good light:


Correct ones:



I thought it may be a matter of diodes maybe.

Thank you in advance.

They look like scratches on the negatives. Hold the negative up to the light and see if they extend into the spaces between the images.

If they are scratches, look at the film path, espeically the presure plate, to see if there is anything there which could be scratching your film.