1981 RCA VFT-650 has me stumped

[Blast]

Computer tells me I worked on three VFT650's in the early to mid 90's (and, one PV-1770) but all were not anything considered to be a 'dog', as this one sounds like it may be.

It does sound like the classic dirty mode switch, however. You might try some contact cleaner in the switch.

[Ed in Tx]

Yep many times odd mechanism operation can be the mode switch. I don't recall if those have the load-unload complete leaf switches at the rear of the mechanism like some old top-loaders had.

Those were loaded with alignments for SP LP and SLP servos norm, ff & rev search, cylinder servos norm ff rev search still and slow tracking presets PG phase + and - , head peaking, all sorts of adjustments. I think the RCA version only had SP and SLP record, only play LP tapes? Anyway don't go turning things! Unless you have the service manual and oscilloscope.

[Blast]

True. Could be individual switches, indeed. It only had to be "loaded", or "not". There wasn't all that "in between" crap that came along later.