Nakamichi Dragon

Serial #23214-Professionally serviced by Perry Esposito.  
All new belts and idler tire. 
Alignment and locking of the tape guide posts in place for best operation in FWD & REV.
Dolby levels set (both directions), meter levels and test tone levels. 
All 3 heads aligned with Nakamichi gauges for tilt, height, stroke, and azimuth. 
Calibration of NAAC response per the service manual.
Distortion, frequency response, linearity, W&F, servo feedback response of the quartz locked capstan drives adjusted, and Cue, Start, Stop positions, and reel motor torque adjusted for spec operation. 
All bearings and motor shafts lubricated. 
Capacitors replaced as required. 
W&F in both directions is superb, about the best I've ever seen on any deck, well below the .018% original spec.
Automatic Azimuth via NAAC is also superb, in both directions. The additional work was performed as requested and as I have seen on other Dragons, the response to the micro relays was excellent, with a significantly more stable azimuth over the entire frequency range, and a lower noise floor compared to stock 4066.
Flattened out the response some with an added mod, and you can see that the results were superb with an EXTREMELY flat frequency response, even at 0dB with Dolby C, and as can be also seen, L&R tracking are fantastic, which the relays also contribute to, as there is zero resistance difference per channels with it.
The record/playback plots are for TypeI & IV, (TypeII looks basically identical) just to show that basically no matter what tape you throw at it, it will record & playback from +/-1.5dB from 15 to over  which is less than half the original spec, and it will even do that with a TypeIV tape with Dolby C at 0dB!..There are VERY few decks that can do that.
Added a Mumetal shield around the transformer to reduce the EMF 60Hz hum that is often picked up in this deck, and I did a deep clean of the faceplate, knobs, and keypad areas, as they were fairly heavy with some kind normal cleaner resistant dirt.
On top of that,  once the transport was completely rebuilt, the supply capstan had unregulated high speed rotation, which I was able to diagnose and found a failed 5081AP comparator chip on the motor control board. Mechanically, probably long before you got it, the deck obviously had been sitting around unused for a very long time, (years) with apparently a few attempts to see if it operated. The idler tire was, of course, stone like in condition, and had been sitting against the reel tables contact surface in a few places for years at a time. The old rubber off-gasses a corrosive  that eats away the plastic reel table, making it useless as it thumps and pops, so both had to be replaced. I also found the NAAC worm gear receiver nylon cracked, so that had to be repaired to prevent the brass insert from expelling during operation. The stuck pinch roller arm was removed, cleaned and lubricated and realigned. Most all old grease had become very sticky and had to be cleaned off, then regreased, in the transport, the NAAC, and the azimuth adjust head block slide. The capstans, heads, tape guides and rollers were “put away” uncleaned with significant tape oxide build up, that required soaking and extensive cleaning to return to good operating condition. The build up on all 3 heads was particularly heavy, but thankfully did finally came clean. The very good news is that the heads are in superb operating shape and provide a full range frequency response in both playback and record, with low distortion and W&F is very close to spec in both directions now. NAAC works very well, as designed.