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Author Topic: Amiga motherboard (A3000) cleanup with Isopropyl alcohol: weird results  (Read 5070 times)

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Offline da9000Topic starter

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Hey guys,

following a lot of the suggestions on the forum about cleaning a battery spill with Isopropyl alcohol, I decided to be a bit more aggresive (in the past I cleaned the regions attacked by the spilled battery contents, acid in crystalized form, as far as I can tell, but it didn't do any good, my A3000 was still dead and showing a green screen. I replaced the soldered Chip RAM with sockets, but still no go).

So I poured copious amounts of isopropyl on the various 'infected' areas and then let it sit for a few minutes, then took the board and shook it to take the large amounts of alcohol off, and then used a blow drier (in cold-air mode) and had it blow on the board for a few hours to dry it out. Anyways, the most weird (to me) thing happened: there's various sediments, white in color, over various pins, both on the upper side of the board, but especially visible on the underside of the board, even in places where I wouldn't think the acid has crept to (Chip RAM area).

Has anyone seen this before? Is it what's left after the alcohol reacted (if it did) with the acid or acidic crystals? Could it be something else? According to some searching results isopropyl + sulfuric acid = propylene gas, but I doubt NiCD batteries contain sulfuric acid, as the name suggest Nickel and Cadmium.

I tried adding images in the Hardware section, but they don't seem to appear :(  Let's try here... OK, can't do it either :( The 'image manager' button doesn't really draw properly, and neither does it have a way to load a photo. Can someone help with photos/images ?


Observations:

1) it comes off easily with an old toothbrush
2) it seems to be like fine dust, like a white salt (not the kind you put in your food)
3) it's almost always around pins (or rather where pins stick out from the bottom of the motherboard), but also (less often) around pins going into the motherboard, from the top side

UPDATE:
Photo 1:


And a link:
http://www.amiga.org/gallery/index.php?n=1821=11
 

Offline amiga_3k

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Re: Amiga motherboard (A3000) cleanup with Isopropyl alcohol: weird results
« Reply #1 on: January 13, 2007, 11:44:51 AM »
About photos: They seem to take a few hours to get actually available. When they are, you can add them to this thread. If you don't have the patience, put the pictures somewhere on the net and link them using the little button sitting just left of the bigger buttoen 'picture manager'.

About the residu: I had a mate writing my chemistry reports bacause I didn't understand it back then. Nothing much has changed ever since tho ;-). My humble advice would be to brush the residu of the board gently.

What you should be looking at is vanished traces in the PCB. The accid from the battery first eats its way thru the protective paint of the PCB and when that's gone the copper traces become victim. You might need to repair traces to solve the problems! This sounds like a hell of a job (and it is) but it could be done even with thin, insulated wires.
Get a SAM, while you can! The new AMIGA is here!
 

Offline Framiga

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Re: Amiga motherboard (A3000) cleanup with Isopropyl alcohol: weird results
« Reply #2 on: January 13, 2007, 01:02:30 PM »
take a look here for tech info about RTC repairs. (link "repair section" on bottom page)

 

Offline KThunder

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Re: Amiga motherboard (A3000) cleanup with Isopropyl alcohol: weird results
« Reply #3 on: January 13, 2007, 01:15:02 PM »
belt sander... definitely belt sander


kidding. i would say getting one or two 3000 mobos from centsisift on ebay and transfering your chips would be a good idea. the stuff on your board doesnt sound good but your chips should be good right?

Oh yeah?!?
Well your stupid bit is set,
and its read only!
(my best geek putdown)
 

Offline da9000Topic starter

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Re: Amiga motherboard (A3000) cleanup with Isopropyl alcohol: weird results
« Reply #4 on: January 13, 2007, 02:23:30 PM »
@Amiga_3k:

Ok thanks, I wasn't aware about the delay on the photos. I will wait and edit the previous post. Ok, I just checked: only 1 made it up :( Here it is anyways:
http://www.amiga.org/gallery/index.php?n=1821=11

As for the repair, yes, I'm very aware about the traces. Unfortunately I can't find any bad ones, and even though some people have suggested that since it's a multi-layered board there might be internal damage, I really believe it's not the case, because as I was looking at the board, under a very bright light, I can only see a middle layer(s) under the SMD 68030 CPU itself. The rest of the board does not seem to use the middle layer(s). Especially where the battery was, there doesn't seem to be any via ducts underneath. I'll keep on looking of course...

@Framiga:
Yes, thanks, Castellan's site has been my guide all along! He rules! :) Anyways, I'm not replacing a new battery yet (old has long been removed), because the machine boots to a green screen, so first I have to fix it, then I will add a new battery (probably lithium battery hack or a large coin-capacitor which I bought from www.jameco.com)

@KThunder:
Yes my custom chips are intact. In fact I tried as many as I could (anything that would fit in an A500) and they all worked great! In fact better than the A500's chips! (8372A Agnus would cause "screen trash" while moving windows, while the A3000's 8372B didn't!)
As for centisoft, I don't know... 97% rating and people leaving negative comments, and also last time I contacted him he was kinda avoiding the questions (about shipping for example), so even though it's cheap, I'm afraid I'll end up with 3 more DOA boards, to make a grand total of 4 boards and zero working A3000's ... (EDIT: his auction SEEMs to suggest that you get 3 motherboard, looking at the photo at least, but you only get 1. Centisoft = scumbag )

Maybe I should go check the "vendors" list you guys have been compiling...
 

Offline Framiga

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Re: Amiga motherboard (A3000) cleanup with Isopropyl alcohol: weird results
« Reply #5 on: January 13, 2007, 02:28:40 PM »
@da9000

if this is your mobo you are in a big trouble! :-(

a really weird chemical reaction! and anyway (for future repairs) a good isopropyl alcohol, doesn't needs all the time you spent to dry it out. Sorry but i can't see any good solution (at least looking at the pic)
 

 

Offline da9000Topic starter

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Re: Amiga motherboard (A3000) cleanup with Isopropyl alcohol: weird results
« Reply #6 on: January 13, 2007, 02:49:46 PM »
Hehehe, yeah, it looks like a real mess, doesn't it?

The photo quality sucks, sorry but I don't have my digicam with me right now :(  Anyways this white stuff comes off very easily with a toothbrush... so I'm hoping (and thinking) that it cleaned up anything left over by the battery really well, and pushed it out of the various nooks and crannies.

As for drying out, I don't know how quickly it dried, but I just set the blow drier and let it go, did some other stuff and then got back to it. So maybe not hours, but one hour? Perhaps it dried really quickly, I don't know :/
 

Offline Framiga

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Re: Amiga motherboard (A3000) cleanup with Isopropyl alcohol: weird results
« Reply #7 on: January 13, 2007, 02:57:20 PM »
try to clean as much as possible. With that pic is almost impossible to see anything. Even the solders joint "seems" knackered (or badly reworked)

All the best :-)
 

Offline Jeff

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Re: Amiga motherboard (A3000) cleanup with Isopropyl alcohol: weird results
« Reply #8 on: January 13, 2007, 02:58:34 PM »
I try to avoid comments about specific sellers after taking some heat from "a rude guy in Canada" however I did buy one of those untested A3000 motherboards on ebay you are probably looking at.

It is complete junk, infact you can have mine for the price of packing and shipping if you really want it, I don't:-). It is an early revision unfinished board with TONS of solder work already done, ports missing and damaged, chips missing, ect. To top it off it looks like it was sitting in a stack of 50 or so and then someone played frisby with it.

A3000's are wonderful machines. Don't give up on yours. Either buy one from a trusted person on here, or just hold out for a nice complete one on ebay and interview the seller first asking for extra pictures and information. If it's the one you want just out bid everyone and sit on the extra parts. They usually sell for less than $200.00  Be patient:-D.

Good Luck

Jeff

As for the residue from the alcohol on your board it shouldn't hurt anything. Just get some electronics cleaner, a soft brush, and some compressed air. It should look like new again.
 

Offline Ral-Clan

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Re: Amiga motherboard (A3000) cleanup with Isopropyl alcohol: weird results
« Reply #9 on: January 13, 2007, 03:15:26 PM »
While alcohol is certainly recommended for cleaning electronics (it's fairly benign), it shouldn't take as long as the stuff you had to dry.  Sounds like yours had a lot of water content in it (or you just dumped on a ton).

But I also read somewhere that washing battery acid damage with VINEGAR is a good idea, as it would neutralize any remain acid activity in the residue on the board.

I'm not sure how this would work....wouldn't you need a base to neutralize an acid?  Is the stuff coming out of a burst battery an acid or a base?  White vinegar is an acid (acetic acid).

I know the stuff coming out of a battery is commonly called "battery acid" but perhaps that is just a colloquial term, and it is really a base.
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Offline da9000Topic starter

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Re: Amiga motherboard (A3000) cleanup with Isopropyl alcohol: weird results
« Reply #10 on: January 13, 2007, 03:15:31 PM »
Quote

Jeff wrote:
I try to avoid comments about specific sellers after taking some heat from "a rude guy in Canada" however I did buy one of those untested A3000 motherboards on ebay you are probably looking at.

It is complete junk, infact you can have mine for the price of packing and shipping if you really want it, I don't:-). It is an early revision unfinished board with TONS of solder work already done, ports missing and damaged, chips missing, ect. To top it off it looks like it was sitting in a stack of 50 or so and then someone played frisby with it.


Thank you Jeff!!!!!!!!! That's what I was afraid of!!!!!
Did you buy it from the Centisoft guy? He says he send 3 at a time for $10... but if they are like you said, then what good are they, right?

I'm being patient and calculative. As much as I can. I'm also stubborn so I won't give up easily on trying to fix it. I'm not a newbie with fixing things, although I suck at electronics, but with all the great help from all the Amiga gurus here and some friends of mine, I'm hoping one day I'll figure out the bugger. I really don't think it's anything that serious as the damage was "contained". I just can't SEE it yet...

As for cleaning, I just used a toothbrush and the white residue went away easily enough
 

Offline da9000Topic starter

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Re: Amiga motherboard (A3000) cleanup with Isopropyl alcohol: weird results
« Reply #11 on: January 13, 2007, 03:20:04 PM »
Quote

ral-clan wrote:
While alcohol is certainly recommended for cleaning electronics (it's fairly benign), it shouldn't take as long as the stuff you had to dry.  Sounds like yours had a lot of water content in it (or you just dumped on a ton).

But I also read somewhere that washing battery acid damage with VINEGAR is a good idea, as it would neutralize any remain acid activity in the residue on the board.

I'm not sure how this would work....wouldn't you need a base to neutralize an acid?  Is the stuff coming out of a burst battery an acid or a base?  White vinegar is an acid (acetic acid).


The one I used was typical super-market stuff: 70% isopropyl. As for drying time, I didn't wait for it to dry, I just let it dry, so the fact that it dried after an hour doesn't meant it didn't dry before :) I didn't time it. I'm sure it dried quickly enough.

As for vinegar, I read that in the past and have used it (successfully = no visible harm done), BUT in these forums some of the expert electronics guys advised against using vinegar or baking power, and only using isopropyl. So I'm sticking with isopropyl. It also doesn't smell foul like plain vinegar :)

Note: when I tried vinegar on the "furry" stuff coming out of batteries (in the past), I could hear it "sizzle" or "fizzle" (?) as it was reacting (I'm guessing) with the crystals. I felt like it was doing its job, but that's just a guess on my part. Perhaps it was eating away at my motherboard more quickly?!? (this was on another machine)
 

Offline Framiga

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Re: Amiga motherboard (A3000) cleanup with Isopropyl alcohol: weird results
« Reply #12 on: January 13, 2007, 03:27:22 PM »
sorry but a "The one I used was typical super-market stuff: 70% isopropyl." is out of the game for cleaning electronic stuf!

=>99% is the right number! :-)

 

Offline da9000Topic starter

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Re: Amiga motherboard (A3000) cleanup with Isopropyl alcohol: weird results
« Reply #13 on: January 13, 2007, 03:32:02 PM »
Quote

Framiga wrote:
sorry but a "The one I used was typical super-market stuff: 70% isopropyl." is out of the game for cleaning electronic stuf!

=>99% is the right number! :-)



Couldn't find any :( How is it going to be different?
 

Offline Wol

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Re: Amiga motherboard (A3000) cleanup with Isopropyl alcohol: weird results
« Reply #14 on: January 13, 2007, 03:33:19 PM »
da9000

Looks like a Lead compound to me, possibly
some form of lead sulfide or oxide or nitrate.

It will have formed due to chemical reactions with
the battery electorlyte and or the Isopropyl.
just remove it with a Nylon brush eg: Nail brush or
hard toothbrush.


Wol.
Only after the last tree has been cut down,
Only after the last river has been poisoned,
Only after the last fish has been caught,
Only then will you find that money cannot be eaten.

--- Cree Indian prophecy ---