As the 8mm camcorder ages the circuits that produce the video can drift off frequency. So there's no longer any repair system for these so the best exits are to use Firewire if your cameras have that since that's all digital and not affected by changes in the video output path.
But there's another issue. To get the tapes to play we have to stick to the same make of camcorder and if that fails, we hunt down the exact model the tape was made on.
Finally if a new recording fails, that means that camcorder has issues. Look around for tracking adjustments but no where am I writing that the above will fix this. 8MM is getting about 2 decades old if not more and that's a real problem.
I've been trying to get my 8mm tapes transferred to digital format for months now. I have the software and hardware for my computer (it works perfect transferring tapes from my VCR) and is also supposed to work with camcorders.
However, I have been through two different camcorders, the most recent a samsung SCL860, and I am completely unable to transfer from it (or play it on any household television). The audio buzzes and the image barely works. I'm using the AV cables with it but I'm wondering if I should be using an s video cable? Would that help?
Note that I'm able to watch the tapes back on the camera without any issue. I just can't get it to playback on a television or computer.
I tried recording on a newer tape in case it had to do with mine being too old but couldn't get that to playback either.