Unusual readings while using Morita endomotor (Dentaport Root ZX II)

[Robert Bezhoski]

I would like to know if anyone have had unusual readings (always showing over apex, not showing WL etc.) during endodontic treatment with Morita endomotor (Dentaport Root ZX II)? Could it be malfunction of handpiece? I'm always building up the missing wall before endo-treatment so the NaOCl would not get in contact with the gingiva. This had happened to me in the last couple of treatments. Before it was working just fine, for about one year. I've checked the clamps, the cords and everything seems just fine.
Thank You