Strange line towards top of videotape recording?
 

I was recording a RCA T-120SHG VHS tape when I noticed a strange line towards the top of the recording in VirtualDub. The first 50 minutes of the tape played great and stable. Then all of a sudden a weird line appeared at the top of the video (image attached). I tested it in both my Mitsubishi HS-HD2000U and my JVC SR-VS20 , going into my BVTBC10 and then a ATI AIW USB.

If in fact it is a tape issue, is there anyway to fix this?
whether with TBC adjustments or other methods.

Thank you

Post a sample of the video to see if the defect can be reduced in post-processing

That's tape related, It should be seen if you look closely on the tape surface near the edge. Are you capturing or recording to the tape? If recording just use another tape, if capturing there are some software solutions but it is not going to be any better than what the VCR's DOC did already.

With the above, that looks like a tape scratch, especially it hardly moves on the image and occurs in both fields.

That looks (from the tiny image) like monumentally aggressive drop-out compensation, I guess you need to start doing some crazy tedious AVISynth work. I'd do this in After Effects, there are techniques to improve it, but you've got to be pretty dedicated and start making masks etc to really handle it near-unnoticably.

Unfortunately, there's not a quick solution to that one, the information is 'missing' on the tape.