AVT-8710 and JVC HR-S9900 working correctly?
 

I have a AVT-8710 (black) that has been sitting in my closet for a few years now and don't know if it's working condition. I bought it brand new and have only used it about 10 times. Is there some where I can send it for testing, maybe service?

I also have JVC HR-9900 and Panasonic AG-1970 i'm thinking of unloading. Both in need of repairs. Any ideas? Thanks.

Those black units never worked correctly, flawed as manufactured. Those TBCs are induce dropped frames, and have issues with ghosting, frame sticking, stuttering, and other errors.

9900 is now infamous, a once-great model plagued by it's own fancy DD system.

The AG-1970 (and 1980) are money pits, almost never working now with a costly (~$1000+) major overhaul. I have several decks, and it's a real love/hate relationship. Good image, audio, and tracking, but massively expensive to own and maintain, not at all like JVC decks.

You have the right mindset, JVC/Panasonic S-VHS with line TBC, and frame TBC, but it's just that your gear is bad or failed. You need to replace it. Not trade down, cheap out. Just replace it with quality versions of that same series (JVC S-VHS with line, Cypress/Panasonic frame). My own 1970 is failed, my 9800 is semi-failed, and I have some burnt-out TBCs that failed. It's just hard to keep it working. You're not alone.

Sell it as failed, move on with your video projects. I'm sure you want t6o use gear, not fart around with broken junk, getting nothing accomplished.