I have two suggestions for you:
1. Check with Save On Sound at 5003 Antoine, Suite B. I've had several (non-tape deck) repairs made there, always with good results. The fellow who owns the business (I think his name is "Tom" Tranh) does repair old tape decks. He accepts only cash, and the shop is in a really ratty strip center, complete with burglar bars on the windows, but the man is honest and does good work. As I recall, he keeps only regular 9 to 6, Mon. thru Fri., business hours. You don't want to go there after dark, anyway!
2. Check this website, which is run by a fellow (Rolf) who lives in the Kingwood area (at least he's somewhere just to the north of Houston):
http://www.angelfire.com/electronic2/vintagetx/
I don't think Rolf does any repairs other than on decks he restores and sells himself, although some years back he did check and service a fine Akai 4000 D Mk II I bought on eBay. However, he should be able to point you towards a good third party repair service.
Hope this helps you out. Good luck.