Turbo express controller board repair

[cpsystem3]

Hello! I recently acquired a nice Turbo Express that I am in the process of repairing. It needed new
Caps for audio and video (big shocker there!), that has been done and all is well. The final fault that I'm repairing is with the controller board, specifically the run and select buttons.

At some point, the AA batteries leaked within the unit, corroding over the comm port. Unfortunately the corrosion worked it's way up to the start/run black carbon traces. Where the carbon meets the copper trace, continuity has been lost. How can I go about fixing this? I have concluded the driver chip is OK as I can short the pins and run/select respond just fine.

After I clean up the corrosion, how do I reconnect the carbon with the copper? Can I simply sand it all off and re-tin the traces with solder? Or should I possibly try conductive paint? My unit surely can't be the only one experiencing this problem...

To clarify, the corrosion is directly under where the button lands. I'll try and grab a pic if I'm not being clear.

Thanks for any pointers!
Bill

[cpsystem3]

Possibly this product will help??

http://www.amazon.com/gp/aw/d/B0026PRMVM?pc_redir=1397497651&robot_redir=1

[Keith Courage]

I've glued and soldered in replacement pads from other controller pads before. I just super glued the used pads to the TG express controller board. Pretty sure I cut up an old genesis game pad to do this a few times. It works great.

It shouldn't be too hard for you to do since it is for the select and start buttons. They are kind of out of the way of other parts on the board.

I can't remember if those buttons have copper under them or not. If they do then you can just sand them off and be good to go. I do know that button 1 and 2 do not which is what I had to repair using another controller board before. If you actually have to replace the leads on the board there is a type of conductive tape you can get. Forgot what it actually is called.

[thesteve]

Look for adhesive backed copper foil
It can be cut and soldered as needed

[cpsystem3]

Not the rubber pads.. The pcb itself has corrosion. See the dull copper that's eroded in this pic. Do the suggestions still apply?

https://m.flickr.com/#/photos/81414148@N05/13906944275/sizes/m/

[thesteve]

I know, it works for that too

[Keith Courage]

Oh okay, I thought you were talking about the actual spots where start and select make a connection on the board.

 From your picture I would hardly worry about it. Just clean it up good. Maybe bridge a wire across it if you are not getting a connection through it. That main corroded section at the bottom is just the ground. Also, if the select and start are not working then something else is the problem besides the corrosion because it doesn't look like it ate up all of the grounding line. I bet your rubber pads themselves are bad or need a really good cleaning. Did you try testing out the select and start by using any of the other pads to test it out?

[thesteve]

actually the issue is where the carbon connects to ground on the sel/run buttons
its not making contact.
a conductive pen should be able to repair it, however i would just use a foil contact for the button.
often these boards will corrode like that by the capacitor, causing button I,II inop
in that case i lay a wire strand over the carbon trace and solder both ends
then seal with nail polish

[NightWolve]

then seal with nail polish

Hm, interesting trick/idea... Very MacGyver-esque of you, but that goes without saying with you in general. ;) I'll have to keep this one in mind.

[cpsystem3]

Thanks for the tips guys, I think it'll be wise to do foil on the backside of the conductive rubber, as well as run some wire strands attached to the trace. I have plenty of experience repairing electronics and soldering, just never encountered bad carbon traces.

Also, yes, I tried other rubber contacts on the start button and it was unresponsive. Start activates I and II, so its not the rubber.

I'll report back and let you know how I make out.

[cpsystem3]

Thanks for the tips guys! I soldered a bunch of wire strands and layed them over the carbon traces. Works perfect! You guys are the best

I snagged this unit from a retro game shop in Chicago for $50 last weekend. Some caps and some time and I've got an excellent condition fully working unit. Awesome!! Always wanted one but I'm cheap haha.

Pics of the fix
https://m.flickr.com/#/photos/81414148@N05/13892570452/

Full unit (isn't she nice???)
https://m.flickr.com/#/photos/81414148@N05/13892601362/

Crisp stock screen
https://m.flickr.com/#/photos/81414148@N05/13915781793/