Burned a pad on my first build - Is there any hope for this?

[laundryman]

I was so close to finishing my first PCB attempt with the Mahayana Drive then I messed up on the 9V power jack on the PCB. I did a bad solder on it, desoldered, then continued this cycle several times and now the pad is completely gone and solder won't even come close to forming and sticking at the base on the pad. It just bubbles around it and forms cold solder. Is there any chance at making this work or should I just give up on it?



Thanks.

 

[twebb6778]

Doesn't look salvageable, but don't stress!

You can solder a wire to the underside of this pad instead.

 

[laundryman]

Thanks for the fast response. You just elevated a lot of frustration off my shoulders. So that pad will just have the capacitor on one side, and the 9V+ wire soldered at the same joint on the opposite side? Not sure I worded that correctly. Here is a link to the build documents if needed.

Out of curiosity and for learning sake, how can you identify where another solder connection is possible in lieu of a destroyed one as in my case?

 

[twebb6778]

No worries!

That's a polarity protection diode, it's there to make sure if you accidentally plug it into a centre positive power supply. You could also solder your 9V cable to the top, but it'll be easier and cleaner on the bottom.

I took a look at the schematic and saw that the only components directly linked to the 9V power were this diode and your LED.



If when you power this up your LED isn't working, that's because it's also relying the burnt pad for power.

To fix it, just like these two pads with a piece of wire or some scrap from a component leg.