cangrande wrote:... if any of you have done the capacitor replace (003 didn't you do it?) and you have any additional advice or parts sources I'd love to hear them. Might as well practice my logic board soldering. . . .
JDW wrote:It's best if you have a tweezer soldering tip iron so you can apply heat to both sides of the existing SMD caps at once. It makes them easy to remove and it also lessens the liklihood you will break a trace (which often occurs if you desolder one side, force it up, and then desolder the other side). Of course, a tweezer tip is a bit uncommon, so most people just go the el-cheapo route.
Osgeld wrote:if your using a proper wattage iron there is absolutely ZERO reason to soak the part in heat...
Since we're talking about desoldering caps on the SE/30 logic board, not logic chips, I would like to add some thoughts.
The above statement is correct much of the time, but not all the time. Specifically, when desoldering the two thru-hole axial caps from the SE/30 motherboard, it took a 450°C soldering station and several seconds of heat application before the lead soldered to the Ground Plane would even come loose.
(Those of you who have desoldered those axial caps before should know what I am talking about here.) Since this is a multi-layered circuit board we're talking about here, a soldering wick wasn't much help to me (yes, I tried it more than once in the past on those thru-hole points).
So in cases where one of the leads is soldered to a Ground Plane (or a lot of copper traces on the PCB), you just might need to soak the lead in heat for several seconds with a very hot iron to make it come lose. Since you are desoldering a cap you've most likely clipped of anyway, it really won't do much harm to apply a lot of heat for a longer than normal period of time. Yes, there are limits, but so long as you keep the heat application to around 10 seconds or less, your board will be fine.
An alternative technique is to melt a lump of fresh solder on a fussy lead that is attached to a Ground Plane. Heat up that solder blob for several seconds and usually the lead can then be pulled out with ease by using a pair of needle-nose pliers. The point is that when dealing with Ground Planes you need a lot of heat and you will need to keep the soldering iron on the desolder-point for a longer time than would be required to loosen the solder on other connections.
But with regard to SMD caps, I was not thinking about using the clipping suggestion on these. Osgeld is correct that trying to cut off those caps would result in a big mess. I strongly recommend against that. I personally only clip thru-hole components. The easiest and least messy way to remove the SMD caps is either with two irons or with a desoldering station that has a special head for removing SMD caps. I have been successful at both methods.
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