copper tracks damage

Hellos to All again.

I'm still working on my A4000 restoration project, as the main job that is chassis painting and such need lots of time, thing that is scarce, today I decided rather go towards an easier job so I decided to replace al the zorro riser board's capacitors.

I removed all with no problems but doing an overall inspection to the board, just before doing a cleanup, I've found this (sorry, a bit blurry pic) :

http://i1219.photobucket.com/albums/...020419_res.jpg

And this:

http://i1219.photobucket.com/albums/...020421_res.jpg


Seems some copper corrosion to me , I've done some continuity checks and seemed ok but I've no idea of how to sort this issue.

Any Hints?

The "good" side of this is that all the the damage is on the ground layer so if some scratching and debris removal of the damaged area should be done, It will be easier to rework the connections...

Again thanks, and any help will be appreciated.

Bye!

Scratch away the varnish until exposing the corroded copper.

Then a bit of lemon juice (the thing you get from pressed lemon fruits) over the corrosion for not long than 10 minutes to half an hour (pending on ambience temperature).

Then wash with tap water, then pour some IPA.

After that test the continuity again and redo with jump wire if some trace is broken.

After all this process, apply PCB lacquer or (if you are cheap) clear nail varnish.

+1 ^_^

You could use acetone to remove the lacquer or perhaps a fiberglass pen would better if you have not used that stuff before.

Strange pooling on the ground planes... considering where this PCB would be situated I am surpirsed that the onboard battery could be the cause of this, I suspect this is capacitor related.

The other option would be to contact Amiga Kit to see if they have any A4k Zorro3 daughterboards in stock as sometimes they do =)

I would also take the opporunity to inspect the motherboard on the CPU side of the Zorro 3 socket for leaky / faulty caps.

:Doh:

Forgot to tell about the capacitors!:Doh::Doh::Doh::Doh::Doh:

Well done, my friend!:nod:

LOL rkauer forgot to say his manrtra, must have been a heavy red wine night :D

Thanks to all!

@rkauer: Ok, thanks for the hint, I suspected that some lemon juice should be used (as seen on other threads about battery damages and such), but I was not certainly sure in this case.

I'll look towards some PCB lacquer and adequate tools like a fiberglass pen, as suggested ZetrO, to do it in the right way.

@ZetrO: Yes, looks a bit weird for me also, as this A4000 never suffered battery leakages (just considering a battery leak as a possible cause, wich seems quite difficult, given the distance).

And yes, some of the Mobo's capacitors were in a horrible condition, with leaks and such, but not precisely the ones in that area (i.e. the one between zorro daghuterboard's socket and Ramsey chip), but who knows.

Capacitors... I'll end having nightmares about them! :dry:


Bye!

Quote:

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Originally Posted by cosmicfrog

<SNIP> must have been a heavy red wine night :D

---

No.

As last night (and today, too), I was drinking whisky + cachaça (emptied both bottles, believe me) to fight the cold.

Negative 3°C here. Brrrrrrrrrrrrrrrr. I'm frozen!

Some update:

Well, after listening to a whole set of my family's members repeating at least one zillion times a mantra like: "why are you bothering whith that junk, when you can buy a brand new PC at mediamarkt for about 300 euros" :roll:

I've done some progresses today, as said, I scratched the lacquer (but with an screwdriver, I'm quite an specialist on un-proper tools usage :p), then applied some lemon juice for about 20 minutes, copper looks perfect now and with no real big damage, the corrosion seemed only superficial.


http://i1219.photobucket.com/albums/...1020663res.jpg

Then I rinsed it with tap water (and by the way, I took the chance to clean up the whole board) and then poured some IPA to it, Just to realize that I forgot to scratch and treat the two pins the at the right, dammit!. :Doh:

Well I'll let it dry this night and then treat those two pin's area tomorrow.

Bye!

awesome stuff!

remember to put some coating lacquer when you are done, this will protect the copper from oxidizing with the atmosphere.

if you cannot find any spray PCB protectorant, then clear nail varnish will do =)

On a later note, I'll redo the wheezy solders as seems the cause of it get through the hole affecting the other side.

Nothing really hard to do if you use the proper tools (in this case, a strong enough soldering iron and flux).

Sorry to not observe your creed in improper tools. :p