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My DVMark Micro50 head has a problem with the aux. input cutting in and out. I would like to look at it and see if maybe just re-flowing a solder joint would do the trick.
I took the cover off the amp and now I'm wondering if there is anything in here that, like tube amps, stores a lot of current and could shock me! I don't want to damage the amp, and I sure don't want to damage myself.
For those curious, here's the insides:
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10-15-2019 11:15 AM
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There may be stored current in the amp's capacitors, but it should dissipate after a couple of days, and is unlikely to be at high voltage in any event. That said, it can be very tricky to reflow joints on these 'surface mount component' boards, and make sure you don't use a high wattage soldering iron; a 12w iron should do it . Won't it void the warranty though?
Anyway, it should be easy enough to track the aux socket to its mounting board, provide the connections aren't covered in that white gunk. Perhaps try some switch cleaner first, just to eliminate dirty contacts
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I have heard that if you strum a chord while turning an amp off that the dangerous current dissipates from the Caps. Is this true or is it an old guitarists tale?
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I've also heard that if you play "Giant Steps" you can chase your crowd out of the club,lol!
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There are generally no dangerous caps in a solid state amp, because there is no need for them. Playing notes while turning off a tube amp has no effect on capacitors that I'm aware of.
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Not if you play I Get A Kick Out Of You..
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Don't give up your day jobs guys....
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Originally Posted by sgosnell
But it won't be an issue here if the caps are allowed to drain for 24 h
I'd say anyone getting involved with amp DIY ought to invest in a multimeter; it can avoid a lot of potential trouble.
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Actually playing in club's is getting rare period. At least if you are over 50!
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Originally Posted by lawson-stone
But, if you've rarely used the jack, have never stressed it, and wiggling doesn't change anything, then you may be dealing with something else. I've had an issue on my Little Jazz with Aux, perhaps having to do with 3 vs 4 conductor cables. If you're using 4 conductor, I'd try a 3 conductor and see if the problem is the same.
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Originally Posted by rpjazzguitar
I'll try a different kind of plug to see what happens. Would be nice if that solved the problem. I hope so, because it looks like the main board is really, really, hard to get out of there to look at the connectors. It would be nice if just a different plug would work.
Here's a clip of what's going on seen from the inside while I gently move the plug side to side on the outside:
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I'm not sure that's a solder joint problem. I think the jack may need to be replaced. Those are mostly plastic, and rather flimsy, and won't take much pressure on the plug. Replacing the jack isn't going to be easy, if you can even find a new one. Good luck with the project.
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Originally Posted by sgosnell
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I'd suggest emailing that video to DV Mark and asking them for help.
I can't see in the video whether you're rocking the solder joint when you do that. Or if, somehow, the tip of the male jack is separating from the section of the female which is supposed to touch it. If it's the latter, you might be able to bend it in to make better contact.
But, usually, when the jack is soldered into the board (which I hate, and I'm sorry to see, since I own the Little Jazz), the problem is that the solder joint gets cracked.
I've had this problem on a bunch of different devices over the years, most recently a JC55. The hard part is exposing the solder joint without breaking something by accident while you work on it.
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Originally Posted by rpjazzguitar
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Originally Posted by lawson-stone
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Originally Posted by Stringswinger
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The 3.5 mini jack is far from being a reliable connector. Unfortunately it's the standard for headphones since the "Walkman" times.
Best would be to replace the socket, but DON'T try to solder on a SMD PCB* with a standard solder iron. You'll ruin it. You need a technician who has a hot air solder unit and experience using it.
It's not really hard to do but everything being so tiny, you need the right tool for the job, big magnifying glass or goggles too BTW... and a reeeeaaaallly calm hand...
Good luck!
*
SMD Surface Mounted device
PCB Printed Circuit Board
Lucy’s Jazz Guitar Gretsch G5420 an Projects
Today, 08:13 PM in Guitar, Amps & Gizmos