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/