I have been needing to update this thread. Juan at Stereo repair world, first mentioned by Nak700's in this thread, IS very thorough and reliable, he claims to be repairing Nakamichi's and other high end cassette and reel to reels since the late 1970's. The only "con" is that he is not able to do any shipping or receive any decks other than in person. He told me he tried it with a few cassette decks and things would be not as he sent them once they were received.
So far Juan has repaired four decks I brought him. a CR5A which is mine, an LX-5 which belongs to kindms, an LX-5 which has been on permanent loan to me from Tim-roaulduke-, and an MR2 which belongs to my Denver former taping buddy (former as in no longer in the game).
He did several repairs of either parts or sensors which required more than general maintenance. On the MR2, it had a pitch control circuit which was stuck at a certain non 100% pitch, he took it out of the circuitry, maintained the rest of the pinch rollers, sealed lubricant parts and such and the deck is running great. each deck has had at least 20 tapes run through them since getting them back and are all four working as expected.
Of note- there is still one CR5-A which he cannot get to stop doing this odd behaviour of stopping then starting randomly but continuing the signal output so the stops and starts could be heard on the transfer. He claims to have tried several things and is waiting on part. I find this is not his fault after all, 40 year old legacy gear and he is not charging me for this analysis since I paid him for a maintenance on it.
If on East coast, especially New York, Long Island, New Jersey, Connecticut I would say the trip is worth it to repair these fine old machines. WOULD recommend to a friend!
http://www.stereorepairworld.com/ (631) 697 5850 Juan