Test Jig: How to make reliable connections

I built a DIY test jig for my project.

The goal is be able to test completed preamp boards easily without soldering wires to the board under test. The boards go to customers and I want to keep it as pristine as possible, but fully tested and confirmed to be working.

But I'm having problems making reliable connections. I used millmax pins and sockets. On a base PCB (which is a duplicate of the actual assembled PCB), I soldered some pins, and put the assembled PCB on top, using pins to secure them to the other PCB's millmax sockets.

The pads I need to connect are V+, Gnd, V-, +48, and XLR input 1,2,3 and XLR output 1,2,3.

The problem is not all of the pins/pads make good contact with the top PCB. This becomes problematic especially when power pins are making intermittent contact.

So what is a good method? Maybe a spring loaded contact point? Or just using alligator clips hooked up to component leads?

Ideas?

[quote author="owel"]I built a DIY test jig for my project.

The goal is be able to test completed preamp boards easily without soldering wires to the board under test. The boards go to customers and I want to keep it as pristine as possible, but fully tested and confirmed to be working.
<snip>
So what is a good method? Maybe a spring loaded contact point? Or just using alligator clips hooked up to component leads?

Ideas?[/quote]

The weapons of choice here are called "pogo pins" - internally spring loaded contacts used for "bed of nails" testbeds. They come with a variety of ends and in a number of sizes. RS Components and Farnell (Newark) carry them (at a price).

M

Thanks mobyd... will check them out.

I found some MillMax products, spring loaded contacts but the prices are unbelievable... will check these pogo pins.

The weapons of choice here are called "pogo pins" - internally spring loaded contacts used for "bed of nails" testbeds.

Click to expand...

Thanks mobyd for that tip!

I found some pogo pins on eBay. Built my test jig... tested it, and it works great. No more intermittent connections when testing boards... (No more loud popping and nasty surprises!)

It just takes a few seconds to plop an assembled board in, turn on power and test.

Some photos:

For the record, that's AKA a "bed of nails" test fixture.

JR