TI-59: PC-100A print head fixable?

[Tinue]

Yesterday I got a PC-100A printer, along with a TI-59. When I print, several rows are missing. 40 years ago, I would have used the head cleaning sheet to remove dust, but this is not the problem today:

   

The head looks clean, so I guess some of the individual heating elements are dead. I don't think that this is fixable. Short of finding a replacement print head there is probably no remedy for the problem.

Am I right, or is there a way to get the missing rows back?