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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: dandelion on September 15, 2003, 09:41:36 AM
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Following my recent post, the A4000 arrived on Friday. Yesterday I had the opportunity to peer under the bonnet and was shocked to find two things..
a) Battery corrosion!
The battery is starting to fur up around its poles, not only that, but there's a thing green fur spead out over a few adjacent chips and on the pins of a nearby connector. Please say I can salvage this, that it isn't some unstoppable cancer that will in time short the board. And how can I safely remove the battery? I don't feel very confident with a soldering iron - can I just carefully saw it off?
b) The buster chip..oh dear - it's SURFACE MOUNTED!
I tried to see what revision it is although it's not obvious. It says SuperBUSTER followed by a stream of numbers, however there is a -09 amongst these numbers so I expect it is indeed a revision nine (uh, oh) surface mounted (UH, OH!!) chip. Is there anything I can do about this or should I just turn my back a graphics cards etc.
c) Oh and one other thing, apart from the problems above the machine is working well. I've installed a larger harddrive which is very snappy on the 040 (coming from a standard 020), but when I try to alter the monitor settings to DblPal or Multiscan productivity and plug it into my PC monitor with my old a1200 adaptor it refuses to display anything. At the moment i'm just using it with a scart lead of a big old TV which I don't think is doing the machine must justice.
Any help greatly received!!!
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UH OH! DM alert!
With the buster chips, you may have problems with only certain cards. I think it's the DMA that is broken.
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As I said before... Get that battery off the board NOW. Best to use a vaccum desoldering iron, available cheaply at radioshack. Take the corrosion leakage off the board with ammonia and a soft toothbrush. I believe Redrumloa has some batteries he'd be willing to part with, but in the mean time the system will work fine without it.
As for Buster... Don't worry about it unless you start having problems with upgrade boards. In that case, find an electronics repair shop that can replace SMT chips.
As for video... Try VGAOnly... You'll have to remove all other drivers to use it. I don't see why Multiscan didn't work, but this should fix you up for the time being.
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For the short term, you could (carefully) use a pair of side cutters to cut the battery out, and clean up the mess surrounding it (I used metho on mine - probably not the most effective, but hey..).
Then later you can solder a new battery in when you feel like it.
IIRC it's just a standard 3.6V battery that you can get at most PC shops. I replaced mine with an off-board battery velcroed to the chassis.
- Paul
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I replaced mine with an off-board battery velcroed to the chassis.
That's what I did in my A4000T. But I'm not sure if the batteries are the same between the A4000 & A4000T.
The A4000T has a 3.6V Lithium cell. I just cut (and twisted) it off.
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Probably a good idea to NOT RUN THE MACHINE UNTIL THE FUZZ IS TAKEN CARE OF. Voltage has this way of accellerating electrochemistry.
On the 2000, you can get in there carefully if you have a good pair of wire snips (the pointy, shortnosed ones that are dished a bit for close cutting.. Just saw them at the local Dollar Tree, if that's any help) ... The 4000 looks like the same thing; you'll probably have to cut the single lead on one side, and bend it up a little to get to the joins on the other side.
http://amiga.org/gallery/photo.php?lid=116 (http://amiga.org/gallery/photo.php?lid=116)
Drop the NiCd off at the local recycling center if you can, or plastic-bag it for household hazardous day; they're a bit toxic to chunk in landfill. (Or at least, do us a favor and wrap it in a few layers of Saran and a ZipLoc if you can't be stuffed the trouble; I don't mind cadmium in the ground as long as it's not leaching in my groundwater!)
Now as to the fuzz... I can never remember if ammonia (basic) or mild acid (vinegar) is supposed to be the right thing for this sort of corrosion. Brush and vacuum what you can manually, first, and if you use either, I'd suggest rinsing it cautiously, *cautiously* with clean water after the fact, so you won't have to worry if you've guessed right. (Just that one edge of the board, use distilled if you're paranoid, try not to get any in that yellow trimmer thing if your board is laid out like that one)... That said, if you've got the board out of the case, I *would* just pour from the bottle of distilled water over the section you've ammonia/vinegarized. Also be careful with your brushing and vacuuming - don't risk dislodging any of the surface mount components in the area. Just try to get off what you can.
After all that, my 'trick' would be to saturate that area of the board in WD-40. It's called "water displacer" for a reason; if you read the whole story behind the junk, it was initially developed to drive moisture out of connectors for the space program. Assuming the board is out of the case, tilt it up, and just go hog-wild with the spray can, whether the board is still wet from your other ministrations or not. Any water trapped under the chips, or for that matter, possibly any hydrous compounds formed by the corrosion, should be floated up and away. If it *is* wet, I'd come back in a few hours and shoot on some more, maybe once more after a day when you think things have dried.
*Then,* after some of the water displacer has evaporated (the stuff is rather volatile, actually, which is why it doesn't last very long on squeaky hinges or case fans; it's not meant to be a persisting lubricant)... maybe 24 hours or so... you can try to carefully brush whatever connector was hit by the corrosion, using more WD-40 if necessary, or some contact cleaner (should be available from Radio Shack, the UK equivalent of Radio Shack, or your local TV repair guy if you can't find it anywhere else).
Your machine will smell like WD-40 when it's warm for a while, but a week of running usually clears that up. Don't be too afraid if the exposed/corroded traces darken when you apply it; what happens is that the battery corrosion eats through the green/clearish mask they put on top of the PCB, creating porous spots - and attacking the traces - but if the machine still works, it works, and you can hope the penetration of the stuff will float up any remaining corrosives out of the metal. Again on the volatility front, don't be worried about permanently insulating any connectors with it, since it was designed for the task, and *will* evaporate eventually (if you can't get something to make good contact immediately after it's been cleaned)... I'd be leery of shooting too much directly into that trimmer, though. (Put a patch of tape over it, if you're worried about your aim. But I'm talking 'putting the little red stem on the can and blasting it right into the component might not be good.')
Do tell us which connector that was, though; it'll help us offer advice.
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<Edit: Posted in the wrong thread! :-o>
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I believe Redrumloa has some batteries he'd be willing to part with, but in the mean time the system will work fine without it.
Yes I have a few left. HERE (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=4598&item=2753548607) is one.
Definately follow the advice given here!! Pull that battery immediately and clean the board!!
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Ok, i'm going to do it this evening. I have a couple of hack saw blades which i've been able to borrow (unfortunately no tin snips). I should be able to cleanly remove it with patience though.
Now, ammonia or vinegar...I work in a biology lab so can pretty much get hold of anything. Might just go with the vingear though, old tooth brush, followed by distilled water and WD40.
As for the pins, tbere in a different place on my board compared to the picture link posted previously. However, they look very much like the pins located next to the simm slots on the amiga.org picture. My motherboard revision is "b" by the way.
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Remember that when using a hacksaw you'll get lots of metal dust...so remember to blow that away.
Sincerely,
-Kenneth Straarup.
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dandelion wrote:
Following my recent post, the A4000 arrived on Friday. Yesterday I had the opportunity to peer under the bonnet and was shocked to find two things..
a) Battery corrosion!
Get that battery off of there! Then do the cleanup measures that other users on here suggest.
For replacing the battery, another option is to do what I did with my A4000T. Jumper pins were soldered in place of the battery. Then it is connected to the board via wires and the battery itself is velcro'ed to the bottom of my tower case as far away from the motherboard as possible. This also makes it very easy to replace again in the future if needed.
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A bit more info on the buster chips is here and what problems revision 9 can cause .a4000 buster info (http://www.lysator.liu.se/amiga/hard/guide/A4000Hardware.guide?Definitive%20Buster) :-) And dont leave the batery to long .
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yep! nothing left to do now, but get those hands dirty these folks on amiga org., has given the best advise. i'd go with the off board battery, i did this on my a500 expanision card about 4 years ago no problems. need to throw them barrel batteries in the trash. seems like i took small wire cutters and cut the battery from the legs and soldered my wires to the tip of the legs. don't forget to use acid free solder.
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SPECIAL ALERT! DON't PUT WD40 ON YOUR MOTHER BOARD....OR ANY OTHER OILS...
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Ok...i've decided against the hacksaw option and have been able to get a soldering iron. As well as this i've also got a solder sucker thing which should be useful for pulling away the molten stuff.
However, i've never really done this before...any soldering tips for a novice?
Oh dear, and some conflict on the WD40 advice. If I don't scrub off the corrosion already on the board is it likely to continue to spread and cause more damage? Or is it the case that once the battery has gone that will be that?
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As well as this i've also got a solder sucker thing which should be useful for pulling away the molten stuff.
Personally I'd recomend you go to a electronics shop and ask for a wick. Let the soldering iron heat up, put the wic on top of what you want removed, and place the tip of the soldering iron on the wic. Watch the wic closely and you will see when the solder melts and gets sucked into the wick. Do this a few times for each post, moving futher down the wick. You'll get to a point where the battery is probably still stuck in place but most of the solder is gone. Then put the iron right on one post at a time while tuging lightly on the battery. You will feel the post come out. Once the battery is completely out use the wick once again to get any left over solder off.
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SPECIAL ALERT! DON't PUT WD40 ON YOUR MOTHER BOARD....OR ANY OTHER OILS...
umm, why? (just wondering)
@redrumloa
Just out of curiousity where do you source your NiMH Varta batteries from? Or is that a trade secret? ;-)
Because I have 2 CDTVs, 1 A600, 2 A1200s, 3 A2000s, 2 A500s, and a CD32 (don't know if that one has a battery, but maybe the SX32?). I already have a NiMH, but that's going in my A3000T in the next few days. So I'm looking at wholesale if possible for a least 10 batteries, but don't want to spend $100. :boohoo:
@dandelion
Make sure it's a 15-30W soldering iron and not one of the industrial strength models.
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To dandelion:
All BS aside, you got screwed dude! My advice to you is to salvage the good parts from that Amiga 4000 and keep them as spare parts. Then buy yourself another Amiga 4000, only this time making sure that you first ask all kinds of questions about the computer. Or you could buy another Amiga 4000 motherboard from eBay, I see them all the time listed. Make sure that before bidding on an Amiga 4000 motherboard that you ask the seller questions like "Is the battery or surrounding area on the motherboard corroded or discolored". Also ask the seller to email you a picture of the battery area of the motherboard. Battery acid corrosion is like a cancer, once it starts it can not be stopped. You WILL eventually have problems with that corroded A4000 motherboard, so REPLACE IT! :-o
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Someone fill me in on the WD-40 hate. A board is fiberglass, epoxy, and copper... and WD-40 was specifically designed for this task. Where does anyone else see a problem?
The worst I can see is that it might be implicated in lifting traces, but 1. it's volatile, so less of a worry than CRC or something, and 2. a board with corrosion lurking within won't be much fun either.
dandelion wrote:
Ok...i've decided against the hacksaw option and have been able to get a soldering iron. As well as this i've also got a solder sucker thing which should be useful for pulling away the molten stuff.
However, i've never really done this before...any soldering tips for a novice?
Tin the iron before use - this involves letting it heat up, and sticking a little solder on it until the tip looks shiny. Use 'rosin core' solder, or lead-free electronics solder if you must. What wattage is the iron? (40W will make fast work of the battery connections, but you'll have to try to move quick to avoid burning anything else.)
Once the tip is shiny, carefully hold it to the less-blobby side of the pin, if there is one. Get that desoldering bulb (or piston-device, or whatever it is... arm it first if it's the piston style) in, and suck the stuff up or hit the trigger. Actually putting a component *in* is a little trickier.
If the iron isn't pre-'tinned,' it might take a little longer for it to heat up the solder, which hopefully won't be a problem here, but you wanted the proper technique. Between sucks, you want to take the iron away, and if you're really paranoid, count to 20 or something before you move in again, to give time for things to cool off. (Probably a good idea, because you don't want to further heat and vent the battery..)
Then, when you think you've got it loose, feel free to apply some heat as you try to peel it up; again, you want it directly on the pins. And try not to burn your fingers, or flick it towards your face as the pin you're angling against comes free.
Oh dear, and some conflict on the WD40 advice. If I don't scrub off the corrosion already on the board is it likely to continue to spread and cause more damage? Or is it the case that once the battery has gone that will be that?
Whatever that crud is, I'd assume it contains enough nasties to continue etching as regular humidity helps hydrate it. (Though most of it is probably simple copper oxides, etched up by the chemicals that already reacted.) Don't go nuts, but go lightly with a cheap plastic paintbrush (tapping the bristles against a nearby ground, like a plugged-in-the-wall computer case first - no need for static damage!) and physically remove what you think you can. Then blast away as much else with canned air or something (being careful not to shoot it back *towards* other less-accessible spots on the board... again, I'd tip it on its edge and let gravity do most of the work), and see how awful the damage looks.
From there, you can decide whether to leave it alone or try all the more drastic techniques described. If nothing else, the aforementioned "contact cleaner," "electronic components cleaner," or "TV Tuner Cleaner" available at your local electronics hut certainly can't hurt - though the last sort usually *does* contain a lubricant, if you want to be paranoid about that. (Should be good on card sockets, dunno if it'd be much use on a board.)
Obviously, don't go applying a hot iron immediately *after* you've sprayed any oil-like substance; do the desoldering work first; having the battery out of the way will give you more room for cleanup.
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... Then buy yourself another Amiga 4000, ...
:-o
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@dandelion
If you can get ahold of it, use cleaning grade freon (ie: non-lubricated tuner cleaner). Completely non-conductive, and unlike WD-40, non-flammable.
The battery redrumloa has is perfect for the job. Professional looking, NiMH so it won't leak like NiCD.
As for soldering, what you have is perfect. Just heat up the pin, wet it with a little solder, then suck it out with the vaccum tool. It should suck clean.