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I need help to fix/replace a DC jack.

I messed it up and the board I need to fix used batteries as well but now they wont work because I butchered the DC pads.

Is there a way to bypass the DC jack and make it able to use the battery again? The DC jack I used had 3 prongs and the old one had 5. I got desperate and stupidly tried to solder it on.

I'm clueless with electronics. The DC jack was wobbly and I had to bend the power cable severely to make it work, so I tried swapping it out with a random jack found online.

SP-202 Sampler schematics link is here.

There is a slight crack on the corner of the PCB and because I poorly attached a different DC jack, the pads lifted when removing the old one. Now the battery supply won't even work, I assume because where the DC jack was the circuit loop is broken.

The old DC jack had 5 prongs, I could only find 3 prong DC jacks online How can I attach a 3 prong DC jack to the board when there are 5 originally? Would there be a way to isolate the DC input altogether if that would be easier to do than fixing the pads and trying to attach the wrong part?

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Null
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Elemental Blendz
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    The correct jack part number is HEC2392-01-150. If you can't find that, you should at least be able to use the part datasheet to understand which parts from other manufacturers are compatible with it. – Justme May 30 '21 at 13:55
  • ive searched for along time for that part, i couldn't find anything, just one company years ago that used to make them, but not anymore. so i resorted to buying a jack by matching its looks, i didn't realise the different amount of prongs until i took out the old one. after i resized there were 5 feet i looked online for any dc jack with 5 feet and couldn't find anything. only 3 and 4. – Elemental Blendz May 30 '21 at 15:04
  • I don't even know much about electronics so i cant identify what prong does what (earth/ground, positive/negative)? would the board work without anything attached to the pads? (missing dc jack), apparently the battery's should still work but they stopped after i removed and attempted to replace the dc jack. – Elemental Blendz May 30 '21 at 15:04
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    You've lifted the pads. This isn't going to be an easy replacement. – Hearth May 30 '21 at 17:09
  • yeah the thing is getting a replacement or fixing it to work with the battery and no dc jack, just empty pads, not sure if you can make it work without connecting a dc jack, i c ant read schematics. and i dont know how to substitute for a different model jack, ive got replacement ones but they only have three legs to solder not 5, i wouldn't know what to do to connect it, thats why im hear asking for someone good with electronics how to do it – Elemental Blendz May 30 '21 at 18:51

2 Answers2

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You can make it work but be aware of the role of jack pins 3 and 5.

When the plug is not inserted pin 3 is connected to pin 2 and pin 5 is connected to pin 4. When the plug is inserted these connections are broken.

As for the damaged pads, you can use an xacto knife to carefully scrape away some of the solder mask. This will expose the underlying copper area which you can to solder to.

One idea would be to use the existing jack (assuming it still works) and run wires from it to the pads.

ErikR
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  • i had someone tell me in a discord chat, that i can wire pad 3 to pad 5 and it should activate the battery to power it on. is this correct? – Elemental Blendz May 31 '21 at 00:30
  • https://imgur.com/1wGfR7f – Elemental Blendz May 31 '21 at 00:34
  • pin 1 is definitely ground. pin 2 is where the positive DC voltage should be applied. The only thing is that you should make sure pin 5 is not shorted to pin 4. physically inserting the plug will separate the two. more info here: https://electronics.stackexchange.com/a/90531/95488 – ErikR May 31 '21 at 00:41
  • i was just going to take off the dc jack and wire up 3 to 5 and only use the battery's, i shouldn't need to wire any other pads, right? – Elemental Blendz May 31 '21 at 00:44
  • connecting a battery to TP1 and TP2 might work, but it's not clear just from the schematic what the intended purpose of those points are... I'd have a careful look at the rest of the board. Are they connected to anything else? – ErikR May 31 '21 at 00:46
  • those points are the battery i think – Elemental Blendz May 31 '21 at 00:48
  • anyway im gonna try out wiring pad 3 to 5. only one way to find out. thanks – Elemental Blendz May 31 '21 at 00:49
  • You should connect the barrel jack connector lateral pin, positive terminal, to point 2 (red) in the PCB. Do not connect it to point 4 (also red), because it needs to pass through an inductor (L16) and protection diode (D2). The barrel jack connector switch pin should be connected to the battery positive terminal, at point 5 (blue) in the PCB. – Elemental Blendz May 31 '21 at 00:52
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the ugliest hack-job, old wires soldered 3 to 5 didn't work, then added 1 to 5 so in the end pad 3 and 1 to pad 5 WORKED!! never would have expected it to function. its messy but it does the job

the ugliest hack-job, old wires soldered 3 to 5 didn't work, then added 1 to 5 so in the end pad 3 and 1 to pad 5 WORKED!! never would have expected it to function. its messy but it does the job

Edit (relized i solded 2 to 5 not 1 to 5. It works, but after pad 2 there is the inductor L16 and the D2 diode, there will be a voltage drop in the diode, so your batteries will last less time)

Elemental Blendz
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    None of the joints are correctly made. It may work now but might fail when it starts building oxidation over time. Also you've splattered solder "balls" all over - you need to clean those up or they will fall off and cause a short circuit somewhere. They are only sticking to the solder mask for now by an accidental glue effect from the flux. Overall, this is one seriously ugly patch and might break at any moment. What you should have done from the start is to ask help from someone who knows soldering. De-soldering components attached to large ground planes isn't easy. – Lundin May 31 '21 at 08:02
  • Yeah i know its really messed up, but its more or so to see if i can get it to work, one day when i have the patience ill go back and clean it up, maybe even get a dc jack on it working. i literally found the wires and solder on the garage floor, i didn't take care in the job. ill prob clean it up when i replace the volume pot (its not turning up), post he photo on some redit hack job sub lol – Elemental Blendz May 31 '21 at 09:38
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    basically you need to learn how to solder. Tine the wires, flux, that kind of thing. There are YT vids I'm sure. What you've done works now as a repair, but is not likely to work for very long. – danmcb May 31 '21 at 13:08