DMP-3 Repair? Help Please.

  • Thread starter Thread starter Erockrazor
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Erockrazor

Erockrazor

I mix in (2x) real-time
Hopefully this isn't in the wrong place.

Okay, lets cut to the chase. I bought a dmp3 about two years ago so my warranty is kaput. My first channel doesnt work properly. The channel gives off a very buzzy loud sound (when the gain knob is 1/2 way turned). Then once the gain pot is turned more than halfway, the audio cuts out. I opened up the DMP3 to check out the looks of things but my amateur eyes couldn't tell if anything was wrong. The channel still passes signal but with the noise included. The second channel seems to work fine though.

Any way you guys could help direct me? I dont want to fork out the replacement fee's just yet.

Thanks a lot, Eric.:)
 
It sounds like it could just be a Bad or badly Scratchy Pot...You might try replaceing the Pot and see if that helps.....

The symptoms sound like there could also be a bad Capacitor somewere But I am just scratching at the dark here ,There really is no way to know without takeing it to someone who has the proper test equipment and experience to diagnose the problem....


Cheers
 
Thanks for your help minion! I might have to send it back to m-audio.:eek:
 
It will probably cost more to pay someone to diagnose the problem and fix it. Perhaps just buy a new one, then you'll have three working channels.
 
Yeah, unfortunately, like many home appliances, gear at that price level is essentially disposable. The bench fee at your local electronics repair shop is likely at least $40-60 or so.
 
Hopefully this isn't in the wrong place.

Okay, lets cut to the chase. I bought a dmp3 about two years ago so my warranty is kaput. My first channel doesnt work properly. The channel gives off a very buzzy loud sound (when the gain knob is 1/2 way turned). Then once the gain pot is turned more than halfway, the audio cuts out. I opened up the DMP3 to check out the looks of things but my amateur eyes couldn't tell if anything was wrong. The channel still passes signal but with the noise included. The second channel seems to work fine though.

Any way you guys could help direct me? I dont want to fork out the replacement fee's just yet.

Thanks a lot, Eric.:)

It sounds like a circuit that is being swamped with DC voltage where there shouldn't be any e.g. a leaky blocking cap for the gain control.

I have no idea what is in the DMP as far as circuitry so I'm limited to speculation...
 
This is saddening. I gotta start looking at more pre's or maybe I can score dmp3 a bit cheaper used or something. Thanks for the help guys.:)
 
yes it sucks when gear doesn't work.

you have one good channel and one kind of working channel, below 50% working.....

you have to open it up and spray some pot cleaner in there and some basic things....maybe an obvious problem. seems interesting it works fine until you tweak the pot though.

pics would be great... there's some good troubleshooters around this forum. :D
 
Thanks Coolcat,

Your optimism is refreshing. I like the thought of hope!

I will try and take a picture tomorrow of the insides. Maybe someone can make some sort of diagnosis.

I'm willing to tinker, but blindly tinkering on my part wouldn't be smart.

Thanks, Eric
 
Hopefully this isn't in the wrong place.

Okay, lets cut to the chase. I bought a dmp3 about two years ago so my warranty is kaput. My first channel doesnt work properly. The channel gives off a very buzzy loud sound (when the gain knob is 1/2 way turned). Then once the gain pot is turned more than halfway, the audio cuts out. I opened up the DMP3 to check out the looks of things but my amateur eyes couldn't tell if anything was wrong. The channel still passes signal but with the noise included. The second channel seems to work fine though.

Any way you guys could help direct me? I dont want to fork out the replacement fee's just yet.

Thanks a lot, Eric.:)

If you want to isolate if the pot is the problem just use a jumper wire across the pot leads to take it out of the circuit. If there is buzzing and noise thereafter, it could be a bad etch or a bad op-amp. I really doubt if a cap would be the offender unless it has an open on one of the legs.

It is most (to least) likely:
1. Bad solder joint(s)
2. Bad/dirty pot
3. Bad Op-Amp
4. Bad etch (intermittant connection)

The unit is only 2 years old. It is highly unlikely that a component (other than the IC pre-amp chip) has gone bad. So, if you want to tinker, you know where to look now.

First, look at the whole PC board with a good magnifying glass. Look at every single connection for cracks (especially at connectors/pot legs/etc.)
Any solder connection that looks funny/dark/hazy/pitted should be re-soldered. After this, try the steps above to isolate the problem.

I would say that 98% of problems like these are manufacturing defects and 98% of those defects are solder problems. This is very true in manufacturing and most people tend to not believe how easy fixing today's electronics is.

Good Luck!
 
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