DIY Articles fix it yourself
RX-505 switch cleaning procedure
RX-505 Dolby On-Off / Dolby B-C / Eq 70-120 switches no longer lock in place? Here’s the fix!
Sankyo control motor cleaning procedure
On Nakamichi decks that have a Sankyo-made tape transport, it is common to see a problem develop where the deck's tape transport starts to act very strangely, and the deck may even stop responding to commands.
Orange Cap replacement procedure
It is observed that large number of Nakamichi cassette decks start behaving strangely after years of use or storage (with very limited use) mainly due to certain make of capacitors losing their properties.
BX-300 Mode Motor Repair
The motor used in Sankyo transport decks is a major source of problems in these aging decks. The problem is seen as a deck that seems to not respond to front panel controls (play, stop, rewind, etc.) and on some decks where the transport mode lights flash after an attempted mode change. This is caused by a dead spot that has formed on the control motor stator. A short term fix is to open the deck and give the motor shaft a little nudge. This usually gets it out of that dead spot, but, it will get stuck again. Some people have had success with spraying Caig Labs, DeoxIT into the holes on the back of the motor and cycling the deck through the modes several times. A better solution is to remove the motor from the transport and after spraying in the DeoxIT to let it run for several minutes using an external power source between 4-9 Volts. This will help the motor brushed to scrap away the carbon in the dead spot. A more permanent solution is to disassemble the motor and use very fine grit sandpaper or steel wool to clean the stator while spinning the thing with and electric drill. Apply some DeoxIT and reassemble. There is one more possible solution. Replace the motor. Now these motors are no longer available from Nakamichi, but, two suitable replacements have been found that will require a few minutes of modification to the deck. The Mabuchi RF-370C-15370 motor from MCM Electronics for $32.65 (out of stock at last check) is a very close substitute. The Johnson RF-370C, P/N 174693 motor from Jameco Robot Store, for $2.49 has a slightly longer shaft, but, it will work fine. The mounting holes are 17mm apart on the motors and 16mm apart on the Nak transport. Take a small rat tail file and elongate the two holes on the transport to mount the new motor.
