Amiga.org
Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: tonyvdb on February 08, 2015, 10:12:21 PM
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So Ive been taking to a friend about my Amiga 4000 intermittent issues. He suggested putting the entire motherboard into the oven at 350F for no more than 10 min to basically reflow the solder.
Seems like sound advice given at this point I have very little to loose.
any thoughts to this?
UPDATE:
I decided to try it and it was fully successful! everything is functioning and no more issues with video dropouts and intermittent ram loss.
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While such a technique has worked for some kinds of equipment, that doesn't necessarily mean it's a good thing for your 4000. Temps hot enough to reflow solder will also potentially melt any of the plastics installed too. What trouble are you having and what steps have you taken so far to try and zero in on the problem?
A method I've used successfully to locate problems is to put light pressure on components or areas one at a time while either watching a good system bootup, or applying with the system running and watching for lockups.
Another is to use a heat gun very selectively.
Depending on the issue you're having, it could also be you have a chip somewhere that's overheating and failing intermittently, or a cracked chip socket.
Plaz
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Using a heat gun while shielding the plastics with aluminum foil is by far safer.
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well the list is rather long,
Intermittent video, I have the Indovision AGA (sometimes video just drops out or does not even show) Ive reset the indovision a couple times.
Ram cuts in and out (already removed and cleaned with eraser and rubbing alc)
I have striped down to the bare motherboard and it still happens if i put pressure on the board in random spots.
The frustration is simply that when I start putting things back in it becomes even more flaky.
I also have issues with my Wico joysticks not working right (not centered and work strange)
Ive posted questions on these issues here and it just seems to be the age of the motherboard in general.
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I wouldn't do it, considering the age (fragility) and value of the board, better to send it to someone like like Anthony Hoffman in NZ.
Not to say it isn't possible, but I have yet to see one of those boards flaky or dead due only to a poor solder joint. I have however seen them with lots of other problems, that a home "bakejob" won't fix (SMD capacitors being the obvious one). Motherboard RAM cutting in and out, if not a contact issue with the SIMM is generally some sort of damage from battery leakage.
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Not a really a good idea to do that. Pull the board and inspect for non shiny solder joints. If you see some, re-solder by hand. If you see none send for recap and cleaning. It's not expensive.
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But for full diagnostics and repair, consider Amigakit or (come September) Anthony Hoffman in NZ.
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As well as the capacitors might also be the power supply, don't mess with it send it away to a specialist so it can be given a full service, it will be worth it.
Don't forget the A4000 was released in 1992 (23 years old) :)
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Well, I decided to try it because I love to live dangerously LOL
Let it cool and put everything back together and low and behold, everything is working 100%!
I still have to test the joysticks but all ram is reporting, no more video dropouts and nothing is visibly wrong.
On a side note I towerised the A4000d a long time ago and replaced the power supply with a good quality 400watt ATX PS and modded the connector so it would fit the motherboard. The battery was replaced a few years back and there was no damage from the previous one.
A Happy Camper :)
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May the Lord bless you and keep your Amigas safe!
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Amen.
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Wow. How did the plastic RAM sockets go?
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The ram sockets did fine (I removed the ram when I did this as well as the 3640). The only part that seems to have been slightly warped and I mean slightly was the Buster 11 chip socket however as I said everything is working perfectly :)
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So Ive been taking to a friend about my Amiga 4000 intermittent issues. He suggested putting the entire motherboard into the oven at 350F for no more than 10 min to basically reflow the solder.
Seems like sound advice given at this point I have very little to loose.
any thoughts to this?
UPDATE:
I decided to try it and it was fully successful! everything is functioning and no more issues with video dropouts and intermittent ram loss.
What I would tell you is to check the solder joints.
I wouldn't put a mother board into any oven.
An oven for solder reflow is different than your home oven.
You risk drying up the capacitors.
There is special solder equipment for solder reflow and it usually is done with a soldering station (hot air station) that has a heat gun so you don't add the heat to parts that don't need it.
https://learn.adafruit.com/adafruit-guide-excellent-soldering/making-a-good-solder-joint
See page #25:
https://learn.adafruit.com/downloads/pdf/adafruit-guide-excellent-soldering.pdf
To reflow, you are probably better off with a hot air rework station:
http://www.circuitspecialists.com/hot-air-station
And don't forget to use flux.
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Chuck, its a wee bit late for your advise, and while putting a motherboard in a kitchen oven is, "Bold talk for a one-eyed fat man" (True Grit 1969), it is done and seems to have worked to the satisfaction of the owner. He appears to have considered the outcomes and made his decision.
Bravo! But, "Son, you're on your own..." (Blazing Saddles 1974)
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Just out of curiosity would a heat shrink gun (paint remover) work?
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wow congrats that's amazing:) you should go play the lottery right away because it seems your luck rate is very high right now:hammer:
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Just out of curiosity would a heat shrink gun (paint remover) work?
Leaded solder and unleaded solder have different temperatures they melt at. It also depends on whether Commodore used a cheap or normal mixture of solder.
I think whoever wants to do this kind of work should take lessons and ask questions from people in the industry and they can be found on microcontroller boards. There are fewer experts than there are hobbyists.
People should learn about temperatures, leaded solder and non-leaded solder, reflow ovens, heat reflow guns. surface mount soldering and also watch some videos on it.
You might actually need a heat sink and you can also damage components with regular soldering.
Common solder formulations based on tin and lead are listed below. The fraction represent percentage of tin first, then lead, totaling 100%:
63/37: melts at 183 °C (361 °F) (eutectic: the only mixture that melts at a point, instead of over a range)
60/40: melts between 183–190 °C (361–374 °F)
50/50: melts between 183–215 °C (361–419 °F)
http://en.wikipedia.org/wiki/Soldering
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wow congrats that's amazing:) you should go play the lottery right away because it seems your luck rate is very high right now:hammer:
PowerBall is up to $450 Million. If you win, buy up all the rights/licensing/trademarks to Amiga. I suspect you'll need to spend at least half of that on lawyers. :roflmao:
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Just out of curiosity would a heat shrink gun (paint remover) work?
I guess you will be the person to find out, but a soldering work station for SMD components runs around $100 for a basic model (from China) and you can set electronically the temperatures used.
[http://www.ebay.com/itm/NEW-USA-Brand-GQ-5200-hot-tweezer-SMD-Rework-station-hot-air-soldering-Iron-/121368272784?pt=LH_DefaultDomain_2&hash=item1c421cdf90]
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Chuck, its a wee bit late for your advise, and while putting a motherboard in a kitchen oven is, "Bold talk for a one-eyed fat man" (True Grit 1969), it is done and seems to have worked to the satisfaction of the owner. He appears to have considered the outcomes and made his decision.
Bravo! But, "Son, you're on your own..." (Blazing Saddles 1974)
Just because it apparently "worked" doesn't mean it will work for everyone and there is no rule that says solder will reflow evenly. Solder joints have to be checked.
There is no rule that says it won't damage other systems.
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Do I need to re-copy my posts? What do you think my posts have been saying? At what point did I say, "this is the perfect solution?"
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No. But ask some electronics experts at Microchip, Atmel, Adafruit, Dangerous Prototypes, Sparkfun or even Hackaday and ask how to properly go about it.
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Why?
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Why?
I care enough about the users to more properly direct them how to do electronics and I would not put an Amiga in my stove.
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But you don't care enough to read the posts? How odd!
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Pah, it's a common procedure especially with video cards about 5 to 7 years ago as the first ROHS compliant solderings didn't work too well. But mostly it's just a temporary solution.
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Frontal lobectomies used to be a common procedure too, but I still wouldn't recommend one
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So, here is everything back together and running.
So far no glitches :)
Bottom tower is the A4000 Top tower is the 7 SCSI hard drives for Flyer
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So, here is everything back together and running.
Impressive setup!
:banana: :banana: :banana: