Repair help - MM Sub4 bass output issue

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Repair help - MM Sub4 bass output issue

Postby Andrew McSpadden » Tue May 22, 2018 10:07 am

I got a MM Sub4 , standard single HB and active electronics 4 string, that has a weird output issue. It only has out put when the string is struck hard and then only briefly and distorted. Battery is good and the pickup reads 6.35K. Solder joints and connections look good. Any suggestions?
Andrew McSpadden
 
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Re: Repair help - MM Sub4 bass output issue

Postby David King » Tue May 22, 2018 12:33 pm

Do you get the same result when the battery is removed? #1 most common issue is the battery leads breaking off or the battery clip not making a good connection. Many active basses will behave exactly this way without the battery.
David King
 
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Re: Repair help - MM Sub4 bass output issue

Postby Andrew McSpadden » Tue May 22, 2018 12:58 pm

I think I found it. a diode or transistor on the PCB was fried and fell off when I touched it. Contacted MM to see if I can get a replacement.

Thanks for looking and responding!
Andrew McSpadden
 
Posts: 31
Joined: Wed Jan 02, 2013 4:28 pm

Re: Repair help - MM Sub4 bass output issue

Postby David King » Tue May 22, 2018 10:09 pm

That's a wild one, I wouldn't have thought a 9V battery could put out enough of a sustained current to cause that kind of damage. The other question is was it just one bad transistor/diode or was there another failed component that caused the one to fry.
David King
 
Posts: 2431
Joined: Sat Jan 07, 2012 10:01 pm
Location: Portland, OR


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