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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: Nick_66 on May 22, 2016, 12:41:50 PM
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I own two Amiga 1200 and both of them still working fine. Thinking of doing a recap of my Amiga's.
Is it a necessary to replace the caps even though both Amiga's are working fine?
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I own two Amiga 1200 and both of them still working fine. Thinking of doing a recap of my Amiga's.
Is it a necessary to replace the caps even though both Amiga's are working fine?
I don't think there is an absolute certainty your caps are failing... But look at it this way, if you don't do it, how do you know you are getting the 100% best Paula audio experience possible? How do you know your audio has not slowly degraded over the years? Maybe there is a whole other level of audio fidelity you are not experiencing?
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If you plan to keep them and enjoy them I would do it. I offer a recap service if you live in the US and charge competitive prices. A few on here should be able to verify my work and who I am if concerned.
Feel free to PM more more info if interested. If you are in Europe I can also give you some good recommendations of people that can do it if they dont reach out before then.
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On the one hand, if it's not broken, why fix it? On the other your A1200 is over 20 years old, and if there is one thing we know for certain regarding those little electrolytic caps inside our Amigas, it is that they will fail eventually.
Already there is a chance they've dried up some, and are leaking current. Caps are designed to do three things: store a bit of energy, block DC and let through AC. So a 'leaky' cap, one that lets DC through at low to no resistance, can at some point decide to cause a direct short to ground which spells all kinds of bad things for your system.
What is a bit annoying, is that unlike say diodes, resistors and transistors, testing caps in system is just about useless. You can only really check for direct short, and even that may give a false reading as you might pick up a signal that takes another route between your probes.
So the alternatives are to assume your caps are good for a while more at least - and change at first sign of your Amiga acting up - or play it safe and just change them now.
When changing by the way, there is no rule that says you have to change with new electrolytics. On the digital only part, Ceramics or Tantalums will last forever. For the Audio circuitry though, electrolytics or oscon caps will yield the best quality - though you could use Ceramics as well if you're not that picky about audio quality.
(One word of caution though: If using Tantalums - triple check you got the polarity right. Get it wrong and they might just explode and burst into flames...)
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I own two Amiga 1200 and both of them still working fine. Thinking of doing a recap of my Amiga's.
Is it a necessary to replace the caps even though both Amiga's are working fine?
Yes if you want to prevent board damage.
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Where can I ask someone for recap of my A1200? I'm from US...
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If you plan to keep them and enjoy them I would do it. I offer a recap service if you live in the US and charge competitive prices. A few on here should be able to verify my work and who I am if concerned.
Feel free to PM more more info if interested. If you are in Europe I can also give you some good recommendations of people that can do it if they dont reach out before then.
Please see above post...
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I want to do this recapping of my A1200 myself. I have all the necessary tools to do this and I am quite handy with a soldering iron.
I saw on Youtube somebody showing how he did a recapping of his A1200 and to remove the old caps he turned them a couple of times with a gripper (is that the correct word for this tool?) to remove them from the circuit board. Is this the best way to remove them?
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I own two Amiga 1200 and both of them still working fine. Thinking of doing a recap of my Amiga's.
Is it a necessary to replace the caps even though both Amiga's are working fine?
Recapping might be a cheap insurance to keep it running for a long time.
Ive ordered recapping for my A1200. Works fine, but Ive started seeing slight distrubances on the screen, which, Im told, is a clear sign that the caps are overdue for a change.
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I saw on Youtube somebody showing how he did a recapping of his A1200 and to remove the old caps he turned them a couple of times with a gripper (is that the correct word for this tool?) to remove them from the circuit board. Is this the best way to remove them?
Oh hell no, don't even try this. You are likely to tear off quite a few pads.
Best method is to have a pair of 'hot tweezers', but that is a bit specialist tool and cost a fair bit. You can use a hot-air station, but be careful. The cap may pop and you'll catch a 300'C piece of metal with your face. Also all that heating of the motherboard may cause micro-cracks in the traces. Which would be very bad news.
In preparation for my own recapping of my A4000 (still waiting for the caps, but should arrive this week), I've used an old PC motherboard to find a nice safe way to remove such caps - and not hurt the pads or the mobo.
What I've landed on is using two soldering irons as a sort of improvised hot tweezers. Both with a fairly chunky chisel type tip for max heat transfer. With an iron in each hand, each side of the cap get heated. After two-three seconds it'll begin to move, at which point one can just tip it off and away or lift off and drop somewhere.
Works a charm, and exposes the mobo to the least amount of stress both physical and from heat - and keeps the pads still very much attached to the motherboard 100% guaranteed.
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I came accross this video on Youtube:
https://www.youtube.com/watch?v=EaEA85r380g
After about 3 min he shows how he removes the caps. Looks very easy.
In this video you can clearly see that these caps are seated on a piece of plastic. You can't reach the soldering pads.
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I own two Amiga 1200 and both of them still working fine. Thinking of doing a recap of my Amiga's.
Is it a necessary to replace the caps even though both Amiga's are working fine?
it's only necessary if you want to keep using your Amiag for another 20+ years else it's optional as those old caps can start leaking any minute now...unless they haven't already started slightly leaking pouring that acid all over those fine traces and contact pads;)
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PLEASE dont "twist" off the old caps. If you dont want to let someone like me that knows how to do it correctly than please at least do it right. Use a GOOD soldering iron and practice on an old board. Good to a thrift store and get an old VCR or something like that. Tear it down and use it to practice.
The hot air rework station is how I do it most of the time. You can also use an iron if you are quick and heat each side while using a pair of ESD tweezers. The problem people run into is the cost of getting everything you need to do the job correctly is more than jsut paying someone to do it. If you dont plan to use the stuff more and decide to go cheap, well its asking for problems.
Here is the list of caps you need:
Digi Key Link: http://www.digikey.com/short/3pbwnr
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The hot air rework station is how I do it most of the time.
This is what i got recently:
http://www.amazon.com/Kendal-REWORK-SOLDERING-IRON-STATION/dp/B004ZB9D4O
Unfortunately the price has increased $10 but if you are thinking of tying this yourself, one of these Chinese soldering stations may be what you need. I think these come with bunch of different brand names, but look to be the same thing.
I assembled several of these "flickering flame" kits and the quality of my work improved so much (over the $15 wand) that its hard to believe it was soldered by the same person.
I may attempt the A1200 myself, I just always thought it entailed removing surface mounted caps which I'm reluctant to attempt.
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I do have a good soldering station with a couple of soldering tips. One is a very sharp tip and a bigger (flat at the end) one. I can regulate the temperature of this station. I also have a suction pump and litz wire.
Can I reach the soldering tabs of the cap on the circuit board? Do they stick out underneath the piece of plastic?
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Here's a nice start-to-finish of (one method) replacing SM caps
https://www.youtube.com/watch?v=mjCa0DAEpzQ
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Great video. I too am looking to do this myself. What is the gel used at 2:30 of the video?
Here's a nice start-to-finish of (one method) replacing SM caps
https://www.youtube.com/watch?v=mjCa0DAEpzQ
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Great video. I too am looking to do this myself. What is the gel used at 2:30 of the video?
Solder paste. Solder and flux mixed together.
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I saw on Youtube somebody showing how he did a recapping of his A1200 and to remove the old caps he turned them a couple of times with a gripper (is that the correct word for this tool?) to remove them from the circuit board. Is this the best way to remove them?
I run an electronics assembly line - and as others have said, DO NOT DO THIS. You will end up tearing pads off the board.
Hot air tools are the best way to go, and you can find them cheap on Amazon or eBay. Cover areas that you don't want to affect with kapton tape.
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Here's a nice start-to-finish of (one method) replacing SM caps
https://www.youtube.com/watch?v=mjCa0DAEpzQ
That video do indeed show the proper way of doing recap work. However, it is also done using quite specialist tools.
Like the hot tweezers, which your garden variety enthusiast and hobbyist have no good reason to throw money at. You can though achieve much the same effect using two soldering irons. Just make sure both can reach good temperature (at least ~350'C / 670'F) *AND* retain heat well.
I use a Hakko soldering station with a beefy chisel tip (3mm i think) and a cheap as dirt 30W 'all in one' soldering iron with a similar chisel tip. Just pre-tin the cap with a blob of solder on each side for better heat transfer, get the irons in there and see the solder melt and simply tip away the cap. Easy as icecream and 100% safe for your Amigas precious pads. Every time an Amiga pad is torn, a kitten cries! Clean the pads with a touch of flux, solder-wick to suck up the remains and then rinse the area with isoprop and a lint-free swab or tissue.
As for attaching new caps, again the video is very proper and professional. And again it is using something an enthusiast won't have just lying around usually - solder paste. solder paste is fickle stuff that cost quite a bit _and_ got an expiration date of about a year after manufacture, assuming you store it in the fridge. Solder paste is great for SMD reflow work, but to justify buying the stuff, one better do quite an amount of SMD reflow work.
Another method is to just use a bit of flux and good old solder wire. Add a drop of flux to one pad, then place the cap the way you'd like it to go. Keep in mind that electrolytics are polarized, so it do matter which way round they are attached.
Anyhow, with the cap in place and the drop of flux on the one pad, melt a little solder on the tip of your iron to create a tiny blob of solder on it. Now use this blob to 'tack' on the cap on the side where you applied the flux whilst you hold down the cap with some tweezers or similar so that it do not move about. Once done, clean the tip, and solder on the other side properly. Then move to solder on the first side properly. And done.
Next cap please!
:)
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Just found something on the internet. It's a SMD tweezer soldering iron:
SMD tweezer (https://www.reichelt.de/Diverse-Loetkolben/TWEEZER-SMD/3/index.html?ACTION=3&GROUPID=4136&ARTICLE=87411&OFFSET=16&SID=11VfjXoawQATMAACUl-3447d2895dadb24c876984f42d41d200b9&LANGUAGE=EN)
It's affordable but will it work?
Or this one? (https://www.conrad.nl/nl/star-tec-st-505-smd-soldeer-desoldeerpincet-st-505-tweezer-588740.html?WT.mc_id=gshop&insert=8J&gclid=CKP9pYPJ-MwCFc1uGwodMQoP2Q&tid=211354628_36781341188_pla-189927245828_pla-588740&WT.srch=1)
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Just found something on the internet. It's a SMD tweezer soldering iron:
SMD tweezer (https://www.reichelt.de/Diverse-Loetkolben/TWEEZER-SMD/3/index.html?ACTION=3&GROUPID=4136&ARTICLE=87411&OFFSET=16&SID=11VfjXoawQATMAACUl-3447d2895dadb24c876984f42d41d200b9&LANGUAGE=EN)
It's affordable but will it work?
Or this one? (https://www.conrad.nl/nl/star-tec-st-505-smd-soldeer-desoldeerpincet-st-505-tweezer-588740.html?WT.mc_id=gshop&insert=8J&gclid=CKP9pYPJ-MwCFc1uGwodMQoP2Q&tid=211354628_36781341188_pla-189927245828_pla-588740&WT.srch=1)
I use a Weller $200 set and they are my favorite tool. Work amazingly well as long as you know how to use them properly.
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Just found something on the internet. It's a SMD tweezer soldering iron:
SMD tweezer (https://www.reichelt.de/Diverse-Loetkolben/TWEEZER-SMD/3/index.html?ACTION=3&GROUPID=4136&ARTICLE=87411&OFFSET=16&SID=11VfjXoawQATMAACUl-3447d2895dadb24c876984f42d41d200b9&LANGUAGE=EN)
It's affordable but will it work?
Or this one? (https://www.conrad.nl/nl/star-tec-st-505-smd-soldeer-desoldeerpincet-st-505-tweezer-588740.html?WT.mc_id=gshop&insert=8J&gclid=CKP9pYPJ-MwCFc1uGwodMQoP2Q&tid=211354628_36781341188_pla-189927245828_pla-588740&WT.srch=1)
They both seem a bit anemic. The top one only 20W per element, and the bottom one a smidge better at 25W. Add to that the rather thin tips, and you have pretty poor heating power coupled with pretty poor heat mass and heat transfer surface.
They may be perfect for lifting off small components such as resistors and ceramic/tantalum caps. But the electrolytic SMD caps have significantly more heat absorption mass. Maybe even so much that those hot tweezers will either struggle or fail at removing them altogether.
Have you looked into getting some quick chip solder (https://www.adafruit.com/product/2660)? With it you can lift off SMD components using just a (good) soldering iron. Cheaper than hot tweezers too. Or, do as I do, use two soldering irons.
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LOL!!!! Proud Navy Retired Chief
Didn't know Chiefs knew how to work!!!
You know how to use a Pace?
Didn't think a Chief could do that
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Hey Chief,
Is that a 150 watt or 200 watt soldering iron.
Oh, I could go on with this, but,
How you doing Chief, old HM-15 Alameda giving you harrassment. Retired there and then moved to Florida, told Ca. I would pay their stupid taxes if they kept the roads open long enough for me to get out of their and back to a good state. Then as the situation would happen had to move to Pa. Only difference between Pa and Ca. is that Pa. has very cold weather. Now getting ready to move once again.