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TIP: How to Repair a Barcrest 340240 Step motor MPU3

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Posted (edited)

If your Barcrest MPU3 is a bit noisy when playing, probably it is a defect step motor.

My Razzle Dazzle "I AM DRD 2,5 C" 4 reel machine had for years a noisy B-ROL.

Just humming when the rol spins, just that match that it is was a bit annoying.

Procedure to fix this problem.

First switch over the step motor 7-way plug with a good stepper,

Also switch over the 6-way Photo-coupler plug of both the chosen steppers. Other wise you get an alarm.

Now play a game or through the test option and test if the noisy step motor is also moved to the new location.

Of course the pictures are wrong but that cpu doesn't know that.

In this way you cancel out the reel motor-pcb or a MPU problem.

 

If you figured out it is the step motor that is noisy,

Test coil resistance

BN-BK and O-R app. 56 Ohm. 4 Coils separately measure app. 28 Ohm

Test if the axle of that noisy motor has some kind of front-to-back clearance.

If so the motor is a repair option. Do the following.

 

- First mark the reels A,B,C,(D) so you know the original order because the reels are all different.

- Dismantle the reel assembly.

-Unscrew 3 Philips screws that attached the plastic reel to the axle module.

-Take off that plastic reel (position mark isn't necessary the cpu lines-up with the hole and photo-coupler)

-Tap out that small black pin

-Take off the last axle unit.

- With a heat-gun and a knife blade gently peel of the backplate of the motor.

MARK !! the coils are in plastic cover so heat up till max. 50C, just enough to heat up the glue.

-Take out at the front axle that C-clip, remember the take off amount of washers.

- Take out the inner motor rotor unit.

-Look inside that rotor and you will find a spring washer, that is the problem maker.

-Find a washer, or a couple of them, fill up at the inner side of this rotor, just enough that there is a tiny little pressure

when mounted back and washers with C-clip is mounted again.

That is that spring-washer is doing his job again.

But keep that spring washer inside it has the function off tension the rotor all times.

A bit trail and error.

-A drip of clear tinny oil on the shaft.

-Mount every thing back-worth

-Play the came and found out that it is completely quite again.

 

Worked for me that is.

Have fun,

Maurice

 

 

 

20190106_Barcrest 340240-Stepmotor-001.jpg

20190106_Barcrest 340240-Stepmotor-002.jpg

20190106_Barcrest 340240-Stepmotor-003.jpg

20190106_Barcrest 340240-Stepmotor-004.jpg

Edited by maurice_nl
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Thanks for that maurice very interesting .

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Great,thanks for sharing

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You're a brave man, not something I would attempt. I thought I'd read somewhere that once a stepper was stripped down and reassembled it never worked as well again? Can't remember the reasoning behind it. Point for discussion perhaps?

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i have a few large boxes of mpu3 motors if anyone cant be bothered todo a strip down , also there are definitely more decks and motors that can be stripped for spares than machines

 

interesting thread though . and good to see stuff being done 

 

thanks for sharing :) and the time its taken you todo it 

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@midibob,

Taken this motor apart will not destroy the magnetic gauge.

Though careful with that ferrite core.

A for example a loudspeaker magnet indeed don't take that magnet apart it has a magnetic short plate and indeed if

that is the case it will lose some magnetic gauge. Can take it of the chassis but leave magnetic complete.

So if you find a situation where the magnet it self is a construction of ferrite and metal plate(s) don't ever take those apart.

 

@riche100 , Yeh if I had a couple of motor's ....

But this is quite an easy job, just took one hour and that is including figuring out the problem, how to dismantle the motor

and looking for a washer in a pile of screws,nuts,bolts,metal things box.....

 

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I feel bad for dumping bad MPU4 motors in the pass. Thought they were impossible to repair 

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On 1/8/2019 at 8:05 AM, midibob said:

You're a brave man, not something I would attempt. I thought I'd read somewhere that once a stepper was stripped down and reassembled it never worked as well again? Can't remember the reasoning behind it. Point for discussion perhaps?

The Shinano Kenshi stepper motors found in MPS, Castle and older Electrocoin, etc. DO NOT like to be pulled apart. It seems to dramatically weaken the magnetic field and the reel will just skip all the time.

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2 hours ago, BarcrestPlayers said:

I feel bad for dumping bad MPU4 motors in the pass. Thought they were impossible to repair 

These not alot that can not be repaired 

Just the case of putting the time into

Getting these things working again!

 

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