Hi Im sorry to heart that.
Usually this is just a bad ribbon. I would clean all the contact surfaces no the character block, print head but the guides, then try a brand new ribbon, this should fix this problem. Its pretty common on these sometimes they get a bit of lube oil on those surfaces, then it would also be on the old tape do don't use that one again ;-)
Let me know if this fixes the problem or if we need to go further?
In any case, I will stick with you until this is complete.
Please rate kindly thus far, it won't cost you anything to rate my service to you kindly,
Then you can reach me by simply replying to this message anytime.
Thank you and have a nice day!