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aiwa 880 motor


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#1 davebush

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Posted 01 October 2016 - 04:26 AM

Hey guys n gals.......been trying to get the motor running on a aiwa 880 for hours now....motor is ok...microswitch that switches the motor is ok....iv found a suspect small orange capacitor....if this is open circuit, would that be enough to not let the motor run

 



#2 Helmar

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Posted 01 October 2016 - 09:41 AM

Please Post a picture. Are you sure it is a capacitor? There is a small inductor coil mounted on the motor. If this one is open, then of course the motor will not run. But you could bridge it in the first instance.

#3 Superduper

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Posted 01 October 2016 - 09:56 AM

Dave, to my recollection there is indeed an inductor and it looks like a shrink wrapped coil. Don't guess just test it with your DMM. Should read close to zero ohms.



#4 davebush

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Posted 01 October 2016 - 10:12 AM

Norm. Im not getting a voltage to the motor coming out of the board



#5 JVC Floyd

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Posted 01 October 2016 - 01:10 PM

Sounds like the same thing that happens to m90 when that resistor on the cassette deck motor goes bad.

#6 Superduper

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Posted 01 October 2016 - 05:33 PM

Dave, R202 is a fusible resistor, it has probably blown.  See if you can find a 1/2 watt 1-ohm replacement.



#7 BoomboxLover48

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Posted 01 October 2016 - 05:49 PM

Nice to see lots of help here. Hopefully it is that resistor. Good luck! How nice it would to see all working... :yes:



#8 Superduper

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Posted 01 October 2016 - 08:41 PM

Two ways to test that resistor Dave.

 

(#1), with boombox powered down, check for resistance between the two resistor leads.  You should get 1 ohm.  However, unless you have a high end fluke with lo-ohms mode, you are probably not going to get that kind of accuracy so if you read 2.5 ohms or less, I would say it's OK.

 

(#2) with boombox powered up, CAREFULLY test VOLTALGE with black probe at a known ground, and the red probe at one resistor lead first, then test the other.  You should get voltage at either lead.  If you only see voltage on one of the leads and not the other, then it's blown.  If you get high voltage at one lead and low voltage at the other lead, then resistor is still conducting but insufficiently to do it's job.



#9 davebush

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Posted 02 October 2016 - 02:57 AM

Thanks to everyone.....im on to it now....will report back with results



#10 davebush

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Posted 02 October 2016 - 11:26 AM

ok Norm    ....im getting 1.1 ohms across the R202 but im not getting a voltage either side of it



#11 Superduper

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Posted 02 October 2016 - 03:16 PM

OK.  So I am making some presumptions here.  If my presumptions are incorrect, then you should check those first.

 

(1) WHEN you are testing voltage at R202, the motor switch (S10) must be on.  This may involve manually actuating the switch or depressing play.

(2) You have confirmed that S10 is working properly.

(3) You have confirmed that S10 is getting voltage.  You can verify by testing (live), with meter on DC volts function, black probe on a known ground, red probe on S10 contacts, one at a time.  Without actuation, one contact should read rail voltage, the other should not.  Upon actuation, both contacts should read rail voltage.

 

IF the above presumptions are true, then you most likely have a failure in the motor driver regulator circuit.  The two most common items that fail are either the driver transistor, the regulating zener diode, or both.  If you don't want to test, then just replace both of them.  If you want to verify first, then I'll need (live - switch actuated) voltage measurements of B/C/E of the driver transistor which I believe is Q43 and both pins of D16.  Q43 replacement is not critical if exact replacement part is not available.  Just make sure to replace it with one with equivalent or higher power dissipation capability, and hopefully similar HFE.  Of course if you replace it with a non-exact part, you need to make sure that the pin assignments are connected properly since the pin arrangements B/C/E may not correspond to the new device.



#12 davebush

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Posted 02 October 2016 - 05:18 PM

Thanks Norm....S10 is working as voltage of 16v either side of it........but it does however show that whether its activated or not , there is voltage either side of it so it must be stuck in the make position.....so at least we know its not an open switch circuit...

 

Looks like its the motor driver regulator circuit so ill be back to it after work tomorrow cos its 12-30 am here and i gotta sleep.....

 

I can see q43 but can you shed some light on the regulating zener diode...which one, value etc

 

 

Appreciate all the advice.......much appreciated



#13 davebush

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Posted 31 July 2017 - 10:49 AM

So I finally got this fixed thanks to Norm for his help and advice