Substituting Capstan motor in SONY TCD707 - UK Vintage Radio Repair and Restoration Discussion Forum

'LIVEWIRE?' · 24th Dec 2014, 11:05 am

One of the capstan motors in this 1990s twin deck cassette recordern is faulty and the original ( a Matsushita MMI-6H2LWK) is no longer available. Being 'clever!' I though 'I have a Mabuchi EG-530-K2B which will replace it!'
Both are the same size, 12v CCW dual speed motors with 4-terminal connections (- + A & B, the latter two being for HI/Lo speed change. On the Mabuchi motor it states '1600/3200RPM CCW', but rotational speeds aren't stated on the MMI-6H, and I can find no data on the net. However I went ahead and fitted the Mabuchi motor, using the original pulley, and ensuring that I had wired it correctly to the control circuit only to find that the deck runs in fast mode in play position with no sound from the tape. (I'd already proved that the original motor was faulty by swapping it with the one from the good deck) Am I missing something, or is the Mabuchi motor, which is 'new old stock!' not compatible with the MMI one??

vidjoman · 24th Dec 2014, 6:24 pm

If there is no sound than that must be another fault not connected with the motor. It might be caused by a misplaced lever or something that you may have refitted incorrectly when it was apart.
Most motors will have either inbuilt potentiometers to set the speeds or they are built onto the circuit board.

24th Dec 2014, 11:05 am	#1
'LIVEWIRE?' Rest in Peace Join Date: Mar 2006 Location: N.W. Oxfordshire(Chipping Norton) Posts: 7,306	Substituting Capstan motor in SONY TCD707 One of the capstan motors in this 1990s twin deck cassette recordern is faulty and the original ( a Matsushita MMI-6H2LWK) is no longer available. Being 'clever!' I though 'I have a Mabuchi EG-530-K2B which will replace it!' Both are the same size, 12v CCW dual speed motors with 4-terminal connections (- + A & B, the latter two being for HI/Lo speed change. On the Mabuchi motor it states '1600/3200RPM CCW', but rotational speeds aren't stated on the MMI-6H, and I can find no data on the net. However I went ahead and fitted the Mabuchi motor, using the original pulley, and ensuring that I had wired it correctly to the control circuit only to find that the deck runs in fast mode in play position with no sound from the tape. (I'd already proved that the original motor was faulty by swapping it with the one from the good deck) Am I missing something, or is the Mabuchi motor, which is 'new old stock!' not compatible with the MMI one??

24th Dec 2014, 6:24 pm	#2
vidjoman Dekatron Join Date: Jun 2013 Location: East Sussex, UK. Posts: 3,326	Re: Substituting Capstan motor in SONY TCD707 If there is no sound than that must be another fault not connected with the motor. It might be caused by a misplaced lever or something that you may have refitted incorrectly when it was apart. Most motors will have either inbuilt potentiometers to set the speeds or they are built onto the circuit board.