Midway Power Supply acid question...

ZEN

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Hey all, I have a few 90412 power supplys for Tron, Spy Hunter, Kickman, etc. Trying to repair one, but I have a question about the acid damage. I have a few nice boards that dont work, and have noticed that a few spots on the traces on the boards looked a little "bubbled" underneath the boards green layer, easiest to see on a light box. does this mean These would need repaired? I get some continuity on these when I measure, I have never reflowed a trace before...anyone else had this problem on these, I know the typical stuff....I just want to avoid putting the time and the $22 kit on an unrepairable board..
 
I think all of mine have the bubbling, but I they still work. I think the green stuff is just a coating on top of the actual trace. If in doubt, check the trace with a multimeter.
 
These should be bead blasted or sanded before repair. I wouldn't put any time or parts into a board with corrosion or residue still there. Thing is, in removing the corrosion (which will spread), you might be surprised how much of the traces that still appear ok or show continuity are nearly gone.
 
When you sand the pcb and expose the trace, how do you recover this the ensure its protected etc? I know they sell those pen things, but whats the easieset way, I have never had to bead blast or sand a pcb before....
 
Use 30G wire and repair the traces going from either the nearest component to the nearest component, or using the thru-holes (which is my favorite).
 
Use 30G wire and repair the traces going from either the nearest component to the nearest component, or using the thru-holes (which is my favorite).
I think ZEN meant that if you lightly sand a trace to get the corrosion off and it doesn't eat through the trace, how do you cover it again so it isn't exposed? The green stuff (conformal coating?) is over the original traces, but what should you put over cleaned up traces?
 
Anyone have an answer for this, I guess I question once I sand the traces down, remove the deterioration, I want to cover the traces up again, or do I need to? I would be scared of some wierd arcing, etc as close as some of these are....and what can I use to cover these properly, any type of paint, etc? Any help would rock....
 
Don't worry about arcing, but if you're that worried some electronic supply stores sell repair pens for reapplying the green coating...
 
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