Atari Edge Connector Repair

[andykmv]

...with an epoxy cap it works just as well. The trick is to put as much on the cap as possible without getting any on top of the finger itself. Then carefully sand it back...

i am interested in repairing my pacman pcbs using this technique and am wondering about the following issues:

In your first picture, how did you overlap the foil trace ? it looks like it could be one of two possible approaches:
overlap1 --\
----------- \------\ added foil, starting with overlap on original trace, running to the edge of edge connector
===============
overlap2 -------
----------- ------\ added foil with a seperate piece soldered on top ovelapping both original trace and new foil trace
===============

Epoxy type used for substrate repair: I was thinking of needing to use an epoxy with a hig temperature tolerance such as would occur during soldering (ie 360 degrees centrigrade / 680 F ?) What sort/brand/model of epoxy did you use ? and what did you use for colorant ?
[some epoxy available in hardware shops in aus tend to soften above 60 deg C/140 F, such as might occur when a connection is dirty or arcing]

Adhering the foil to the substrate: I was thinking of using the same epoxy to adhere the foil to the substrate. Have you relied on adhesive backing on the foil to adhere the foil to the substrate ?
If not, what did you use to adhere the foil to the substrate ?
[One AussieArcade forum member noted a pcb purchased from EU prob relied on adhesive backing as the foil peeled back after a few insertions/removals of the card edge connector]

Cheers!

 

[andykmv]

...there is less chance of rolling the foil back when you insert the edge connector into a tight connector. I've had a few repairs do that. Of course, I didn't have adhesive foil and instead had to glue the piece down.....

Following on from my previous post, in your case where the foil rolled back on your repaired finger, what sort/make/brand of glue had you used to adhere the [non-adhesive backed? ] foil to the substrate ? have you found one glue works better than others ?

Cheers!

 

[channelmanic]

Just don't use super glues... They give off toxic fumes when you heat them.

 

[bit_slicer]

I use the first overlap method. And I know what you mean about having to use hi-temp epoxy. Unfortunately you can't rely on the sticky adhesive to adhere to the substrate. It's good for the initial placement, but you have to finish with epoxy. The problem is the epoxy won't stand up to soldering very well. I wrestled with this for a while until I found a way to epoxy *after* you solder. What you do is heat up your iron and dab a small amount of solder on the original stub and spread it around a bit. Then apply the new finger into position and secure it on the leading edge with something like a small spring clamp. Next, pre-wet a length of solder wick, add some flux to the joint, and then drag the solder wick over the joint away from the leading edge. Clean it up, let cool, then you have it anchored on one end. Now you're free to add epoxy to the leading edge, spring clamp again, let dry, sand smooth, and done!

The epoxy I used is 3M Scotch-Weld, although you could use another brand. This one is good up to 139F (59C) which is adequate for a nominal operating environment.

For colorant I tried a few different kinds of paint before settling on plain 'ol Testors enamel. The trick here is to use a very small amount - a little bit goes a long way. And in small amounts it doesn't seem to bother the cure process.

After re-reading through this explanation it occurred to me that a video tutorial might be better. Stay tuned!

i am interested in repairing my pacman pcbs using this technique and am wondering about the following issues:

In your first picture, how did you overlap the foil trace ? it looks like it could be one of two possible approaches:
overlap1 --\
----------- \------\ added foil, starting with overlap on original trace, running to the edge of edge connector
===============
overlap2 -------
----------- ------\ added foil with a seperate piece soldered on top ovelapping both original trace and new foil trace
===============

Epoxy type used for substrate repair: I was thinking of needing to use an epoxy with a hig temperature tolerance such as would occur during soldering (ie 360 degrees centrigrade / 680 F ?) What sort/brand/model of epoxy did you use ? and what did you use for colorant ?
[some epoxy available in hardware shops in aus tend to soften above 60 deg C/140 F, such as might occur when a connection is dirty or arcing]

Adhering the foil to the substrate: I was thinking of using the same epoxy to adhere the foil to the substrate. Have you relied on adhesive backing on the foil to adhere the foil to the substrate ?
If not, what did you use to adhere the foil to the substrate ?
[One AussieArcade forum member noted a pcb purchased from EU prob relied on adhesive backing as the foil peeled back after a few insertions/removals of the card edge connector]

Cheers!

 

[andykmv]

i have started looking at the 3m scotchweld products now, as per your notes. there are a few models such as 2214, 2216, with some product differentiations within the ranges too. can you advise which 3m scotchweld product did you use ? for example "3M™ Scotch-Weld™ Adhesive 2214 Regular " - this has a temperature rating to 250 degrees F

i then started looking at http://www.cotronics.com/vo/cotr/index.htm and they have a nice range of product options.
Cotronics sell the Duralco 4525 compound which you can get in pre-measured 50gram containers, and it has a temp rating of 500 - 600 degrees F, so may be better suited to the task.


Cheers!

 

[Spyridon]

After re-reading through this explanation it occurred to me that a video tutorial might be better. Stay tuned!

Looking forward to that. This was a good thread.

 

[bit_slicer]

Here's the epoxy I used:

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=3M6439-ND

This works fine, but there might be others out there that work better. One downside of this epoxy is it takes days to cure. But once it cures it sands down really nice. I encourage folks to try different epoxies, and then report back here about how it went.

i have started looking at the 3m scotchweld products now, as per your notes. there are a few models such as 2214, 2216, with some product differentiations within the ranges too. can you advise which 3m scotchweld product did you use ? for example "3M™ Scotch-Weld™ Adhesive 2214 Regular " - this has a temperature rating to 250 degrees F

i then started looking at http://www.cotronics.com/vo/cotr/index.htm and they have a nice range of product options.
Cotronics sell the Duralco 4525 compound which you can get in pre-measured 50gram containers, and it has a temp rating of 500 - 600 degrees F, so may be better suited to the task.


Cheers!