Author Topic: Secondhand PreenFM2 repair help  (Read 576 times)

mcfroski420

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Secondhand PreenFM2 repair help
« on: January 14, 2020, 12:04:28 PM »
Hey, so I bought this PreenFM2 off reverb, it was the right price, but it came to me kind of broken, but I got a nice partial refund and it should more than cover the cost of repairing it.

So, the first issue was that it wouldn't turn on. Like the screen would light up and then nothing would happen. But the unit does work with the usb power, so I'm thinking there must be either a bad connection or component in that part of the circuit. If y'all have any suggestions for me on that I'd be appreciative. But honestly I can live with this and it hardly affects its performance in the long run.


The second and more important issue is that the as you increase the volume by turning the volume pot, the audio increases in volume for the first 70% of the turn, then in the last 20% or so the bass followed by the rest of the signal fade out and decrease in volume.

I just sort of figured that it was the potentiometer but I really have no idea. I'm already going to change the volume pot with one i bought online, but Id really like to fix this.

Here are some videos that I made to demo the problem for the dude i bought it off.
Volume Problem: https://www.youtube.com/watch?v=sfMN_ZXsJH0
Power problem: https://www.youtube.com/watch?v=zVO_PUM1Uxw

Xavier

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Re: Secondhand PreenFM2 repair help
« Reply #1 on: January 14, 2020, 02:17:17 PM »
Hey,
Please post a good quality picture of your PCB both side.
That would help to have a first idea of what is possibly faulty and what is not.

mcfroski420

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Re: Secondhand PreenFM2 repair help
« Reply #2 on: January 17, 2020, 05:34:42 AM »
Here’s one

mcfroski420

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Re: Secondhand PreenFM2 repair help
« Reply #3 on: January 17, 2020, 05:41:15 AM »
Files were too large, I took put the pics in this google album. Thanks in advance you guys! https://photos.app.goo.gl/jVprWvaF4HenvTgG8

Xavier

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Re: Secondhand PreenFM2 repair help
« Reply #4 on: January 17, 2020, 08:23:07 AM »
The album is empty.

mcfroski420

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Re: Secondhand PreenFM2 repair help
« Reply #5 on: January 17, 2020, 08:27:43 AM »
They’re up now, my bad

served

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Re: Secondhand PreenFM2 repair help
« Reply #6 on: January 17, 2020, 09:31:39 PM »
I have built this. Years ago.

Change the pot. See if it helps.

Make sure you are feeding 9v DC into PreenFM with correct polarity. Center pos and ring neg.