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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: Super TWiT on June 17, 2011, 09:43:00 PM
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I purchased a ram expansion cover for my a500 a couple weeks back, and so I took off the electrical tape which I had used to cover my 512kb ram expansion. When I took the tape off, it actually took part of the green layer of the circuit board off, exposing a silver layer. I haven't plugged the Amiga in since, and while I think it just took off some paint, I wanted to check here first to make sure I (the tape) didn't break anything.
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I have some pictures (sorry for the quality, lighting is poor!), and on re-examination, it looks pretty nasty. On a side note, I am trying to get to the underside of the a500 motherboard to check some solder points, but I am bocked by that metal shield. How do I take that off? It seems to be locked in place by the thumbscrews on the ports.
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Hmmm. I would probably write that off as a no go. It may be nothing more than some paint, as you suggested, that has come away. However I still wouldnt put it back in just in case it does something wonky once powered up.
You say it's come from a 500?
I may have a spare ram card laying around from my bricked 500. Where abouts do you live? UK or elsewhere?
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Super Twit. I assume you mean you purchased an expansion slot cover, the plastic trapdoor.
Just check that none of the silver tracks were lifted, or broken. If you have a continuity meter you can check each end of a track at the nearest component solder blobs, to make sure it is still a circuit. (while it's not plugged in of course)
Also you need to check that no tracks touch each other broken or burred or lifted from the PCB ! A good magnifying glass will help.
Suggest you then put some good electrical tape over the uncovered spots. Maybe that's what the original tape was there for ?
If you are happy that visually the tracks look okay then it should be okay. The green stuff is a resin coating to protect the PCB tracks and offer some insulation/protection.
PS: From the pics it looks like there may be some lifting at the track edges, just make sure these lifted bits are secure and not burred. IE: They can't touch a neighbouring track.
Apart from that the tracks still LOOK intact.
PPS: As to taking off the shielding I know it comes off as I have removed it before. I guess you are trying to get to the battery? If you post some shots of the shield fixings we might be able to offer suggestions.
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Just solder protection paint coming off - as long as the tracks stay in place there's not much to worry about. Covering the exposed spots with a piece of tape won't hurt though.
If any tracks got lifted off the PCB you'll need to fix them down and ensure that there can be no short. The quick-and-dirty method is using hot glue.
As to the shielding: you'll need to remove all of the port screws in order to take out the board (usually they are not identical). Be careful when putting them back - they're easily overtightened!
In general: I would've used a piece of cardboard to cover the PCB before putting tape over it. That way you can avoid issues like this.
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@CritAnime (http://www.amiga.org/forums/member.php?u=9126) Thanks CritAnime, but I live in the US so I am not sure you'd still want to ship that far.
I have a continuity meter, and a good magnifying glass, so I'll check out the board. The tape wasn't there originally, I put tape across my trap door expansion slot since when I bought the computer, it didn't come with the cover. I recently bought a cover off of ebay, so I removed the tape, and also some pcb pieces.... As for getting to the underside of the amiga, I am having some mouse problems, and I want to check the continuity of the mouse port itself. How would you go about remove the port screws? (you mean the thumbtacks on the ports right?)
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Or you can just use some shellac or clear nail polish to cover up the exposed traces. Just brush it on where needed. Shellac was used on electronics as an insulator in the past (not sure if it has been replaced with a synthetic) so it should be completely safe and inert. Nail polish may be easier to get for the small amount you need.
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@CritAnime (http://www.amiga.org/forums/member.php?u=9126) Thanks CritAnime, but I live in the US so I am not sure you'd still want to ship that far.
I have a continuity meter, and a good magnifying glass, so I'll check out the board. The tape wasn't there originally, I put tape across my trap door expansion slot since when I bought the computer, it didn't come with the cover. I recently bought a cover off of ebay, so I removed the tape, and also some pcb pieces.... As for getting to the underside of the amiga, I am having some mouse problems, and I want to check the continuity of the mouse port itself. How would you go about remove the port screws? (you mean the thumbtacks on the ports right?)
Mouse ports don't usually have problems, Unless a pin has been pushed in(rare), which should be visual. i'd be testing with another mouse, or cleaning up the mouse rollers, sensors etc.