Can dirty heads damage the tape?
 

Like the title says, can dirty/clogged heads damage the tape? I had (have?) a problem where I played 5 different tapes and they all showed a line 1/4 of the way up from the bottom. Mind you all 5 of these tapes have been captured in the past and no line was present. I opened up my VCR (JVC SR-V10U) and cleaned the tape path and heads with 91% isopropyl alcohol and chamois swabs. The swabs definitely ended up dirty and I kept at it until the swabs came out clean. But the five previously used tapes still showed the same line through the picture whereas tapes I pulled out of storage do not show the line. Thanks in advance.

I recently had a good tape play in a VCR with dirty heads and it crinkled the tape, causing new lines to form where the damage was done, so yes, dirty heads can damage tapes.

It's usually the other way around but if the heads got some gunky stuff from a bad tape they could stick to the tape and swing it fast wrapping it around the head. So at the end the question that should be asked is can dirty tapes damage the tape? The answer is definitely yes.