SMD parts size 3216 vs 3528

Everyone Questions and Answers
1

I’m trying to replace a tantalum capacitor on my broken synth.
The original part size is 3216 SMD. Here’s a pic I found of someone else’s repair.

Screenshot 2568-11-25 at 13.48.18
Screenshot 2568-11-25 at 13.48.18793×618 91.6 KB

I found a similar replacement part online, but it’s 3528 SMD.
Does anyone know if it will still fit on the board?
Also, I’m not very familiar with tantalum capacitors. Is there any other reason the part I found won’t work?
Here’s the part I found online:

Screenshot 2568-11-24 at 00.58.52
Screenshot 2568-11-24 at 00.58.521261×778 168 KB

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2

Don’t stress about it fitting!
if it’s just about getting it back working, you can fit almost any SMD cap in by soldering some fine wires to the SMD pads, place the cap upside down on top, wrap the wire over and solder the wires to the cap. You can take a few strands of fine wire from an old cord.
it’s ugly, but it always works. Keep the wires as short as possible.
If it’s subject to vibration, a dab of hot glue or silicone can immobilize the part.

Just be sure the replacement cap has an equal or higher voltage rating.
Obviously there are many parameters to consider, but for most applications, just matching the type and value is good enough.

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3

Hi!

Leo’s right! Wire will allow you to fit something on the board…

If you find yourself struggling with the wire, some folks (like me) use copper tape. It is quite inexpensive and one can usually get it at garden supply stores since it is used to keep snails out of an area.

If you want to use copper here are a couple things that will help:

  • apply the tape with the dull end of a tweezer so it can be pushed down and the adhesion is good
  • it only takes a second to solder tape to a pad so don’t linger on the joint
  • flux is often useful (maybe required) but not too much with the tape since it will reduce adhesion to the board
  • do the tape to extend one of the pads, then place the cap and solder the side without tape, then solder the cap terminal to the tape

The reason I bring this up is that tape works not only for repairs but for so many places where one needs a conductor - I have successfully used it to build RF circuits, low noise analog circuits (like for audio equipment), digital gizmos, etc.

I think one of Leo’s first videos talks about how to use copper clad PCB material and copper tape to build things quickly so you might have a look at that - “Techniques and Strategies for Building Electronic Circuits”

I’m sure you’ve got this working by now but copper tape is so useful I felt compelled to add this.

Thanks for indulging me and good luck with everything!!

All the best

  • Steve
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