Capacitor leakage anyone?

  • Thread starter Thread starter Hrvoje Èièak
  • Start date Start date
David said:
The two biggest things to watch out for is overheating,
causing traces to peel up, and pulling the feedthrough
out along with the lead.
Click to expand...

And overheating is more likely with an underpowered iron than a 40-50W
iron because it takes longer to melt the solder. Lifting of the copper
and pullout of the feedthroughs also happens more with an underpowered
iron since the solder isn't melted as much.
 
johns said:
I am an etech. You can' t go on a multilayer mobo with
a soldering iron ... at all. I have a rework station that
evenly heats all the leads at the same time to exactly the
right temp. That is what it takes, and it works about
half the time.
Click to expand...

Regular electrolytic capacitors aren't nearly as difficult to desolder
as surface mount chips are, but even those chips can usually be removed
with just an ordinary iron and low-temperature solder, such as Chip
Quik. I've used just an iron and desoldering braid to replace several
surface mount chips (but with fewer and thicker pins than what you
probably work on), mostly to fix or upgrade memory modules.
 
You'll ruin that multilayer mobo trying to resolder those
caps. If that thing is out of warranty, I'd toss it and get
another brand. If not, RMA it. Plus, I kind of suspect
that you have a voltage reg blown, and that is what took
out the caps. It may have been the psupply that took out
the Vreg ... or it may have been just heat in the case,
but it would have been around 95 F to do that. If the
box was in sunlight, and turned off, that would do it.
Click to expand...

The last motherboard I bought was a 300-350 MHz Socket 7, while every
board I've obtained since then came from trash cans and usually needed
nothing but new electrolytic capacitors or voltage regulator diodes or
transistors (usually ruined by bad caps). Caps and regulator
components are among the easiest components to desolder and also some
of the cheapest.
 
johns said:
I am an etech. You can' t go on a multilayer mobo with
a soldering iron ... at all. I have a rework station that
evenly heats all the leads at the same time to exactly the
right temp. That is what it takes, and it works about
half the time.
Click to expand...

Whatcha talking about, Willis?

I'm poor and get by just fine with an adjustable soldering iron. I set
it to 50W and use copper braid, but for SMD I use a much lower power
rating. I haven't done big SMD parts, just capacitors, buffers, and
those tiny chips on Maxtor HDs.
 
jeffc said:
Yes but that was far longer than 18 months ago. That can't
be the same problem.
Click to expand...

My 300W Antec is only slightly older than that, but late last year its
Fuhjyyu brand output caps on the +12V rail started to bulge. It had
been running in a 500 MHz K6-2 system that drew only 60-90W and only
1-2A of that from the +12V. OTOH the JGE or some unknown brand caps in
my 300W Powmax made over 5 years ago looked and measured fine with an
ESR meter.
 
David Maynard wrote:




And overheating is more likely with an underpowered iron than a 40-50W
iron because it takes longer to melt the solder. Lifting of the copper
and pullout of the feedthroughs also happens more with an underpowered
iron since the solder isn't melted as much.
Yep.
Click to expand...
 
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