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Author Topic: MMI-6H2LWCI - AIWA AD-WX 888 Pro Tape-Deck (90s) - DC motor disassembly  (Read 60 times)

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Offline Kiriakos GR

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In favor of all times and in order to help technically trained owners of AIWA (japan) AIWA AD-WX 888  & AIWA AD-WX 999 ( Both for professional use Tape-Deck equipment), I am posting these pictures bellow.

MMI-6H2LWCI or similar MMI-6H2LW they do have identical construction.
When such a DC motor starts making motor squeal sound this translates to lots of metallic particles in to both copper bushings.

For such motors there is no quick-fix, motor construction this is close to airtight and dust-proof.

For reliable maintenance it is required complete disassembly.
Both copper bushings should have a bath with WD40 (for several seconds - minutes).
Motor axle cleaning , motor brush cleaning, should be made with fiber glass pencil & corroded contact terminals
New lubrication with Grease, this must be placed from inside to outside at both copper bushings.

If maintenance become with 100% focus on what you are doing and quality work, then motor axle surface will heal (up to a point) after this working for an hour.
MMI-6H2LWCI motor operation will restores to 100% and sound of motor this will restore to normal.

Other details ..........
AIWA AD-WX 888 and similar, they requiring belts of 5mm width and 1mm thickness (original SONY-AIWA belt).
Mechanical issues ( mechanism blockage when selecting PLAY at reverse direction) these could be due dry ed lubrication over plastic sprockets, and also due incompatible belt dimensions.
If you are unable to find the issue, then by pressing rewind button momentarily, the mechanism it does return to synchronization, and reverse side PLAY this will operate.

Yes original SONY-AIWA belt this is not available anywhere ( AIWA this is no more, and SONY does not produce such parts).
Specifications:
Belt inner diameter: 690 mm  ( 6,9 Centimeter) 
Belt Circumference : 216.77
Flat belt thickness: 1mm
Flat belt width:  5mm    (AIWA part 3-9: Flip Disk assy ( black roller) inner wall width this is 5.8mm )
Belt length (side to side when this is positioned flat-down) 108 ~109 mm
(Belt life-cycle 12 years)

At my AIWA AD-WX 888 both motors started making squeal sounds, in the beginning I started suspecting plastic sprockets, but this is a FALSE impression.
I got my AIWA AW-DX 888 when this was best seller product  at 90s ...  this up to date it counts 27 years of life,  and I am now assuming that after such reliable DC motor maintenance, I am going to enjoy it for another 15 years or so.  ;)
 

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Offline Kiriakos GR

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Re: MMI-6H2LWCI - AIWA AD-WX 888 Pro Tape-Deck (90s) - DC motor disassembly
« Reply #1 on: December 12, 2017, 12:30:50 PM »
MMI-6H2LWCI inside world !!!    :)
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Offline Kiriakos GR

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Re: MMI-6H2LWCI - AIWA AD-WX 888 Pro Tape-Deck (90s) - DC motor disassembly
« Reply #2 on: December 13, 2017, 10:10:35 PM »
When you do highly processional work, by 99% chances are that success this is on the way.  ;)
By this post reply, my new recorded log entry this is that at 14 December 2017  my AIWA AD-WX 888 this is restored to factory condition regarding electrical motors.

I did also install new belts, but I am not 100% satisfied, Belt Circumference this is correct but thickness this is only 0.6mm and they are only 4mm wide.
While this machine it is now functional, I will keep looking to find better belts.

AIWA AD-WX 888 this hides one secret, when A or B  cassette deck this is in use, both DC motors of both mechanism they do spinning.     
When non of both mechanism are in actual use, both motors are stopped too, and this translates that both belts (A & B ) they would have identical run-time no matter of actual number of cassettes these played at its one port. 

I am now a bit sentimentally charged  :)  many memories has awaken from the past.
Originally this tape deck were purchased from me as bright new (at price extreme for my wallet back then) , so this to serve at my highest quality hobby studio and this was serving for FM radio broadcast.
Back then there was a local race of whom will deliver best possible sound quality ON AIR.
No more than few months later, CD disk revolution started and specific AIWA AD-WX 888 was not having a heavy work load.
Condition of most parts in it, they seem having run for 1/3 of expected life-cycle (heads, rollers, etc).
Therefore this restoration it did helped one winner model of the past this to stay in activity.
I bet that engineers worked in AIWA, they also take pride by reading such information's over the WEB in our times.

Back then I did skip getting an AIWA AD-WX 999 because I did not care for remote control, and brother model AIWA AD-WX 888 this never ever disappointed me.
One last word of my about DC electric motors, some people in their desperation they spent money getting Mabuchi Motor, well Mabuchi brand at 80s - 90s was Low-end brand, most cheap Hi-Fi and boombox cassette players and even car cassette players, was coming with Mabuchi Motor as standard.
Their DC motors life-cycle was limited to 2~4 years, and personally I have replace many at my repairs shop.

AIWA , SONY and YAMAHA & Panasonic they was a totally higher class of such equipment, with legendary Nakamichi to be famous but a dream for most of us, and AIWA to be a branding that were closest behind Nakamichi, than all other brands.
Therefore in our times, it is worth trying to properly maintenance such quality-made DC motors, because they where made with out planed obsolesce in mind.  ;)       
     
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