2n5457 static protection diode

[acehobojoe]

Do I need to put a static protection diode in my circuit? The 2n5457s seem to keep dying on me. :O I don't know what to do... it's all good until the popping. then more popping.. then it won't work.

[armdnrdy]

Joseph,

I think you should probably post a schematic for the circuit in question.

JFETs don't just "die" 

[acehobojoe]

https://fbcdn-sphotos-c-a.akamaihd.net/hphotos-ak-xfp1/v/t1.0-9/1016856_10155174993965553_1754072877014126956_n.jpg?oh=79a9d7de8e33d3139cdcb3abbd8d25fa&oe=5566E23B&__gda__=1432922987_dc437205203eb88fe6197b99835f77e7


The circuit works fine on the breadboard, but I may have messed it up on my brd file.

https://www.dropbox.com/s/9a0zcneeqvkubwx/live1.brd?dl=0

[armdnrdy]

What circuit is this?

You use dropbox so you can post the images directly to the post.

The Eagle file:

Many members that can offer help don't use Eagle so...they can't open the file.

Save the board image as a PDF and post that with dropbox.

[acehobojoe]

[acehobojoe]

could it be that i did not solder the top of the solder pads? perhaps?

[acehobojoe]

https://www.youtube.com/watch?v=Sp6DiVB7QnU

[armdnrdy]

Anywhere that the bottom trace and the top trace comes together at a pad...the component lead has to be soldered on the top trace to connect the signal, power, gnd, etc, traces together.

You cannot do this with capacitors. (C3) You have to add a Via to connect the two board sides.

How is C1 and C2 soldered if you didn't solder the top pads?

[armdnrdy]

If I may make a suggestion...

Make the board a little larger and spread out the components.

Your traces are way too close to the component pads.

[acehobojoe]

I just soldered the bottom.

[acehobojoe]

Yea, I'll do that. This is my first pcb attempt, so it's a bit redundant and not very neat, but I'll make some new ones.

I'd still like to try to get this one to work.

So anytime you have traces on the top layer it must be soldered on the top?

[armdnrdy]

So anytime you have traces on the top layer it must be soldered on the top?

If it is a place where the top and bottom traces connect at a component lead....yes.

As I stated...that is how the top and bottom traces are connected.

You might want to start with a single sided board.

Double sided boards are very difficult...and not good for your first board.

There are people that have been etching their own boards for years that won't even attempt a double sided board! 

[acehobojoe]

oh.... no, this is a fabbed board. I didn't bother etching.

It really looks great. just don't know if it has errors.

[armdnrdy]

Eagle has commands to check for errors.

ERC & DRC

Look them up on the net and learn how to use them.

[anotherjim]

So the holes are "thru plated", then you don't need to solder top as well as bottom, unless the thru's has failed. But a simple continuity check with the DMM can prove all of them.

Here's what I do, before even powering up, with a clean copy of the circuit, check each component as a separate item and write a check mark thru it on the drawing. A process I know as "correlation"
It gets a check when it's...
Present.
Correct value and rating.
Correct orientation.

...next each connection to that component is confirmed with a DMM continuity test.
Each line connection on the scheme gets a check when...
DMM proves it connects to the other parts of the circuit that the scheme shows that it should.
DMM proves it does not connect to any adjacent pin/trace that it should not connect with.

All checked -  now you can power it up.

BTW, if the design started on a breadboard, when you create the final schematic, use the check method to confirm the scheme shows what you have on the breadboard. Many a slip happens at this point.

[acehobojoe]

Thank you very much for those tips!

[armdnrdy]

Jim's correct about the through hole vias.

I had it in my head that this was a DIY board.

I took a quick look at the board...and beside the fact that there are traces that are much too close to other traces and pads...
I marked a few areas that look like they are touching in the image.

[karbomusic]

Definitely need to download some design rules and use use 'em to check everything before submitting for fabbing if you made this yourself. There are some really good Eagle tutorials around here somewhere. I'd go through all nine or ten of those.

[alanp]

Pretty small holes and pads for components, there.

[acehobojoe]

transistors were backwards in the library too.. .