HELP! Soldering to Spot on PCB

[yellowsnow4free]

Hey everyone!

So I'm in the home stretch of fixing the sync button on my wireless Xbox 360 controller (CG2 board).

I have the switch in place on the board and now I need to solder 2 wires off of it: 1 for ground and 1 to the sync line on the board.

Looking at the Wireless CG2 Traces (https://www.acidmods.com/forum/index.php/topic,34543.0.html), I'll probably solder the ground to TP4 or TP7.  No big deal there, since the contacts are easy to solder to.

But as for the sync line... I'm not sure.  Following the sync line trace, it ends on that chip thing on the back of the motherboard, which looks like a pain to solder to.

Looking at spurgurgle's "360 controller re-design x2" thread (https://www.acidmods.com/forum/index.php/topic,43214.msg323008.html), I saw this picture (https://lh3.googleusercontent.com/-FzDmjRDdLCo/Uqj3mVFZC6I/AAAAAAAABBo/BhxM2rEY8GE/w958-h719-no/analog+wires+wireless.jpg) and noticed it looks like wires are soldered onto the little "holes" in the board; can I solder to these points instead?  If so, how?

Using the board scans provided here, I've drawn this up:



IDK what those little "holes" are called, but it looks like when a trace goes to one of them it continues on the other side of the board.  Can I solder to these points?

Thanks!

[Gizmo613]

They are called vias. And yes you can solder to them but take extra care as once they are screwed up you'll be in deeper  . Take a knife/blade and gently scrape off the solder mask til the copper is exposed then solder as usual. I recommend using a fiberglass pen.

[yellowsnow4free]

They are called vias. And yes you can solder to them but take extra care as once they are screwed up you'll be in deeper . Take a knife/blade and gently scrape off the solder mask til the copper is exposed then solder as usual. I recommend using a fiberglass pen.

Thanks Gizmo613!

So they're called vias, got it (that gives me something to Google for).

It looks like there are some unused vias at the edges of the board, so I can practice on those, right?

In my case, which side of the via's solder mask do I scrape off?  The bottom of the board or the top?  Do I push a wire through the hole or do I simply solder to the pad?

What is the fiberglass pen for?

Is soldering to a via easier than soldering to that chip on the back of the board?

Sorry for all the questions, but I want to be sure I know what I'm getting into before I attempt this

Update: I DID IT

I saved a board from an old Guitar Hero controller that had a similar black chip thingie on it.  I saved it to practice soldering.  Well, my practice went well so I went for it on my controller!

I used blue painter's tape to tape off the adjacent pins, and I checked the adjacent pins with a volt meter after, just to make sure they aren't touching.

Then a quick test on my Xbox 360 and the sync button is working! It doesn't seem to interfere with the right bumper (the closest pin) either

Now for 1 more mod and my controller will be ready for Dark Souls!

[mod]A friendly heads up, use the modify button so u do not double post in the future![/mod]