Somewhat of a success
So for the last... I don't know how long... I've been in the process of working on doing an acid etched circuit board (using instructions from here in order to fix the power supply for the big Biamp board (the board itself now works fine, but the Phantom Power does not and has been traced back to the power supply itself).
The portion of the power supply that is for the phantom power is isolated from the rest of the PCB except for one ground line. After trying to replace a couple suspect components that were targeted while troubleshooting with my friend Steve I ended up getting no love from the phantom power. Enter the site mentioned above; I've decided I'm just going to do a scorched earth fix on the power supply and completely replace that portion of the circuit.
I still haven't gotten a successful etching done yet (I've been having problems getting the toner to stick properly and not come off when removing the paper). I had a couple come out close to perfect so I tried using an etch resist pen to touch up some of the bad traces and the etching turned out fairly good.
Things I've learned/need to do better for the next attempt:
- Use an actual laser printer for printing on the transfer paper I'm using. (this should help with the toner not sticking
- Get more Ferric Chloride. (The bottle I got from a co-worker really isn't enough to etch the size of board I'm working with and make it problematic to get it to etch evenly).
This is what the board looked like after doing the etching (a lot of the traces are still pretty rough and there were some patches that didn't quite etch all the way). I haven't used any acetone to remove the toner/resist pen yet, but this was just a trial run to see if this would even be viable. (This was also an older pattern for the traces, the current one doesn't have any of the text labels, I plan to do a reverse transfer on the back side for labeling where everything is).