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Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
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#1
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Desoldering wattage and tip size for tight multilayer vias
This Saturday I replaced seven popped Nichicon electrolytics
in my iMac G5; it took me nearly five hours of intense battling with too-tight hole sizes and high-thermal conductivity planes but the job got done and the fix worked. Has anyone worked on this planar and can comment? What wattage and tip sizes worked for you? I used a 65 watt iron and ground the tip into various chisels and angled points, used excess solder and flux and tried an amount of preheating but it really was a _bitch_ to do. I kinda doubt the board was made for repairing. Michael |
#2
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Desoldering wattage and tip size for tight multilayer vias
msg wrote: This Saturday I replaced seven popped Nichicon electrolytics in my iMac G5; it took me nearly five hours of intense battling with too-tight hole sizes and high-thermal conductivity planes but the job got done and the fix worked. Has anyone worked on this planar and can comment? What wattage and tip sizes worked for you? I used a 65 watt iron and ground the tip into various chisels and angled points, used excess solder and flux and tried an amount of preheating but it really was a _bitch_ to do. I kinda doubt the board was made for repairing. Michael The heatsinking effect of planes can be a real issue. I use a 140W Weller soldering gun for motherboard capacitor replacement, it's the only thing I've found that puts down enough heat to remove the caps without ripping up traces. |
#3
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Desoldering wattage and tip size for tight multilayer vias
James Sweet wrote:
msg wrote: This Saturday I replaced seven popped Nichicon electrolytics in my iMac G5; it took me nearly five hours of intense battling with too-tight hole sizes and high-thermal conductivity planes but the job got done and the fix worked. Has anyone worked on this planar and can comment? What wattage and tip sizes worked for you? I used a 65 watt iron and ground the tip into various chisels and angled points, used excess solder and flux and tried an amount of preheating but it really was a _bitch_ to do. I kinda doubt the board was made for repairing. Michael The heatsinking effect of planes can be a real issue. I use a 140W Weller soldering gun for motherboard capacitor replacement, it's the only thing I've found that puts down enough heat to remove the caps without ripping up traces. Indeed. I neglected to mention that I cranked up the wattage with a variac to about 90W but that is nowhere near what you use Michael |
#4
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Desoldering wattage and tip size for tight multilayer vias
msg Inscribed thus:
James Sweet wrote: msg wrote: This Saturday I replaced seven popped Nichicon electrolytics in my iMac G5; it took me nearly five hours of intense battling with too-tight hole sizes and high-thermal conductivity planes but the job got done and the fix worked. Has anyone worked on this planar and can comment? What wattage and tip sizes worked for you? I used a 65 watt iron and ground the tip into various chisels and angled points, used excess solder and flux and tried an amount of preheating but it really was a _bitch_ to do. I kinda doubt the board was made for repairing. Michael The heatsinking effect of planes can be a real issue. I use a 140W Weller soldering gun for motherboard capacitor replacement, it's the only thing I've found that puts down enough heat to remove the caps without ripping up traces. Indeed. I neglected to mention that I cranked up the wattage with a variac to about 90W but that is nowhere near what you use Michael Hot air preheating works wonders. I use a hot air paint stripper gun to preheat an area first before then desoldering the cap. Usually they come out of the board quite cleanly but some manufacturers bend the leads after insertion into the pcb, which can be a pain. -- Best Reagrds: Baron. |
#5
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Desoldering wattage and tip size for tight multilayer vias
Baron wrote: msg Inscribed thus: James Sweet wrote: msg wrote: This Saturday I replaced seven popped Nichicon electrolytics in my iMac G5; it took me nearly five hours of intense battling with too-tight hole sizes and high-thermal conductivity planes but the job got done and the fix worked. Has anyone worked on this planar and can comment? What wattage and tip sizes worked for you? I used a 65 watt iron and ground the tip into various chisels and angled points, used excess solder and flux and tried an amount of preheating but it really was a _bitch_ to do. I kinda doubt the board was made for repairing. Michael The heatsinking effect of planes can be a real issue. I use a 140W Weller soldering gun for motherboard capacitor replacement, it's the only thing I've found that puts down enough heat to remove the caps without ripping up traces. Indeed. I neglected to mention that I cranked up the wattage with a variac to about 90W but that is nowhere near what you use Michael Hot air preheating works wonders. I use a hot air paint stripper gun to preheat an area first before then desoldering the cap. Usually they come out of the board quite cleanly but some manufacturers bend the leads after insertion into the pcb, which can be a pain. That's a great idea, I'll have to give it a try next time. Just have to be careful not to overdo it and cause SMT parts to drop off the board. |
#6
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Desoldering wattage and tip size for tight multilayer vias
Baron wrote in message
... msg Inscribed thus: James Sweet wrote: msg wrote: This Saturday I replaced seven popped Nichicon electrolytics in my iMac G5; it took me nearly five hours of intense battling with too-tight hole sizes and high-thermal conductivity planes but the job got done and the fix worked. Has anyone worked on this planar and can comment? What wattage and tip sizes worked for you? I used a 65 watt iron and ground the tip into various chisels and angled points, used excess solder and flux and tried an amount of preheating but it really was a _bitch_ to do. I kinda doubt the board was made for repairing. Michael The heatsinking effect of planes can be a real issue. I use a 140W Weller soldering gun for motherboard capacitor replacement, it's the only thing I've found that puts down enough heat to remove the caps without ripping up traces. Indeed. I neglected to mention that I cranked up the wattage with a variac to about 90W but that is nowhere near what you use Michael Hot air preheating works wonders. I use a hot air paint stripper gun to preheat an area first before then desoldering the cap. Usually they come out of the board quite cleanly but some manufacturers bend the leads after insertion into the pcb, which can be a pain. -- Best Reagrds: Baron. My tool for that is a dart with a bolt exchanged for the flight. Without heating, excavate around the solder with the dart until you can lever the pin up. But then I continue on , using the hot-air only. Another recently discovered aid for this process. I saw a plumber using some woven glass mat to protect a cupboard before soldering. As I had plenty of GRP grade woven mat I glued together 4 bits of sheet of that , using contact adhesive (discolours but holds together on hot air heating). Cut a hole to match the area of interest and lightly clamp the mat to the board , mounted in a vice with protected jaws. -- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on http://home.graffiti.net/diverse:graffiti.net/ |
#7
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Desoldering wattage and tip size for tight multilayer vias
James Sweet wrote in news:Lye1k.2159$Yx.1418
@trndny08: Baron wrote: msg Inscribed thus: James Sweet wrote: msg wrote: This Saturday I replaced seven popped Nichicon electrolytics in my iMac G5; it took me nearly five hours of intense battling with too-tight hole sizes and high-thermal conductivity planes but the job got done and the fix worked. Has anyone worked on this planar and can comment? What wattage and tip sizes worked for you? I used a 65 watt iron and ground the tip into various chisels and angled points, used excess solder and flux and tried an amount of preheating but it really was a _bitch_ to do. I kinda doubt the board was made for repairing. Michael The heatsinking effect of planes can be a real issue. I use a 140W Weller soldering gun for motherboard capacitor replacement, it's the only thing I've found that puts down enough heat to remove the caps without ripping up traces. Indeed. I neglected to mention that I cranked up the wattage with a variac to about 90W but that is nowhere near what you use Michael Hot air preheating works wonders. I use a hot air paint stripper gun to preheat an area first before then desoldering the cap. Usually they come out of the board quite cleanly but some manufacturers bend the leads after insertion into the pcb, which can be a pain. That's a great idea, I'll have to give it a try next time. Just have to be careful not to overdo it and cause SMT parts to drop off the board. I have built dams out of paper to protect nearby parts from the hot air. Held the paper on the board with alligator clips. Works fine. Also a good temperature indicator. If the paper chars too much, your air is too hot. caveat: I was playing with an old pcb, stripping it of parts with my hot air gun. One of the electrolytic caps got caught in the guns nozzle. Before I could shake it out, BANG. Small jet of flames. Shell of cap flying across the room. In other words "avoid overheating electrolytics, they can explode." -- bz 73 de N5BZ k please pardon my infinite ignorance, the set-of-things-I-do-not-know is an infinite set. remove ch100-5 to avoid spam trap |
#8
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Desoldering wattage and tip size for tight multilayer vias
On Mon, 02 Jun 2008 14:11:32 -0500, msg wrote:
This Saturday I replaced seven popped Nichicon electrolytics in my iMac G5; it took me nearly five hours of intense battling with too-tight hole sizes and high-thermal conductivity planes but the job got done and the fix worked. Has anyone worked on this planar and can comment? What wattage and tip sizes worked for you? I used a 65 watt iron and ground the tip into various chisels and angled points, used excess solder and flux and tried an amount of preheating but it really was a _bitch_ to do. I kinda doubt the board was made for repairing. Michael I wouldn't even attempt to do this without a temperature controlled soldering station. You need a lot of power, but with no temperature control, you're likely to over heat the board and lift traces. It's also critical to have a clean properly tinned tip. Andy Cuffe |
#9
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Desoldering wattage and tip size for tight multilayer vias
Andy Cuffe wrote: On Mon, 02 Jun 2008 14:11:32 -0500, msg wrote: This Saturday I replaced seven popped Nichicon electrolytics in my iMac G5; it took me nearly five hours of intense battling with too-tight hole sizes and high-thermal conductivity planes but the job got done and the fix worked. Has anyone worked on this planar and can comment? What wattage and tip sizes worked for you? I used a 65 watt iron and ground the tip into various chisels and angled points, used excess solder and flux and tried an amount of preheating but it really was a _bitch_ to do. I kinda doubt the board was made for repairing. Michael I wouldn't even attempt to do this without a temperature controlled soldering station. You need a lot of power, but with no temperature control, you're likely to over heat the board and lift traces. It's also critical to have a clean properly tinned tip. Andy Cuffe I have one, but it doesn't provide enough heat. 140W gun works great, haven't damaged a board yet, I've been soldering for a long time though. |
#10
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Desoldering wattage and tip size for tight multilayer vias
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#11
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Desoldering wattage and tip size for tight multilayer vias
bz wrote: caveat: I was playing with an old pcb, stripping it of parts with my hot air gun. One of the electrolytic caps got caught in the guns nozzle. Before I could shake it out, BANG. Small jet of flames. Shell of cap flying across the room. In other words "avoid overheating electrolytics, they can explode." Wimp! ;-) -- http://improve-usenet.org/index.html If you have broadband, your ISP may have a NNTP news server included in your account: http://www.usenettools.net/ISP.htm Sporadic E is the Earth's aluminum foil beanie for the 'global warming' sheep. |
#12
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Desoldering wattage and tip size for tight multilayer vias
James Sweet Inscribed thus:
Baron wrote: msg Inscribed thus: James Sweet wrote: msg wrote: This Saturday I replaced seven popped Nichicon electrolytics in my iMac G5; it took me nearly five hours of intense battling with too-tight hole sizes and high-thermal conductivity planes but the job got done and the fix worked. Has anyone worked on this planar and can comment? What wattage and tip sizes worked for you? I used a 65 watt iron and ground the tip into various chisels and angled points, used excess solder and flux and tried an amount of preheating but it really was a _bitch_ to do. I kinda doubt the board was made for repairing. Michael The heatsinking effect of planes can be a real issue. I use a 140W Weller soldering gun for motherboard capacitor replacement, it's the only thing I've found that puts down enough heat to remove the caps without ripping up traces. Indeed. I neglected to mention that I cranked up the wattage with a variac to about 90W but that is nowhere near what you use Michael Hot air preheating works wonders. I use a hot air paint stripper gun to preheat an area first before then desoldering the cap. Usually they come out of the board quite cleanly but some manufacturers bend the leads after insertion into the pcb, which can be a pain. That's a great idea, I'll have to give it a try next time. Just have to be careful not to overdo it and cause SMT parts to drop off the board. I have found that often SMT parts are glued down and are a right pig to get off the board, particularly if its a part that you want to salvage ! -- Best Reagrds: Baron. |
#13
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Desoldering wattage and tip size for tight multilayer vias
That's a great idea, I'll have to give it a try next time. Just have to be careful not to overdo it and cause SMT parts to drop off the board. I have found that often SMT parts are glued down and are a right pig to get off the board, particularly if its a part that you want to salvage ! Often yes, but when you want it to stay on the board, it'll fall right off! Don't ask me how I know that |
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