Please give some suggestions, I'm having a heck of time removing some caps

[JCLA]

About 6 months ago, after about 4 years of use, my computer just wouldn't turn on anymore.
I tested all components and they all worked, so the mobo (intel D845GVSR I think) must've failed, I suspected bad caps but could not see any indication of damage, I just put that motherboard away and used another computer.

Recently I was just cleaning and came upon this mobo again, I gave it a quick inpection and this time I could clearly see a row of 6 bulging caps.

So now I'm trying to replace the bad caps, I would really like to continue using this computer.

A couple of weeks ago I replaced 3 caps on a power supply for my LCD TV, it was very easy.
However, I'm having a hell of time time trying to do the same on this mobo.
First I tried with a 40w soldering iron, that didn' work so I got 60w one.
With the 60w soldering iron one of the the caps came out very easlily, but that's the only one. I couldn't remove the other ones correctly.

The other 5 caps just came off their leads. So now I have the mobo with just the leads from the caps.
I try heating on one side and pulling the leads with pliers from the other side, but the darn things won't come out.

The 60w iron seems hot enough, but still doesn't seem enough to do the job.
Should I use one with a higher wattage? I have a 100 watt one.
What other suggestions do you have?

Thanks very much.

[willawake]

Re: Please give some suggestions, I'm having a heck of time removing some caps

its because probably you are not adding new solder to the existing before removal of the caps

[electroguy75]

Re: Please give some suggestions, I'm having a heck of time removing some caps

as well if u use a 100w iron this would prolly b too hot for copper traces and /or solder pads(it will lift them from mobo) rendering the repair much more difficult if not impossible. really 60 watt is a little overkill lol. as will points out a touch of fresh solder on those joints would go a long way toward removing those caps cheers and good luck friend.

[jpdoe]

Re: Please give some suggestions, I'm having a heck of time removing some caps

You also have to keep the tip clean. Put a folded wet (not dripping) cotton rag on a hard surface, put some solder on the tip, and quickly pass the tip over the rag to clean it.

The more power the iron dissipates, the faster the tip will get dirty.

[kc8adu]

Re: Please give some suggestions, I'm having a heck of time removing some caps

if your iron is not tinned well you will have a rough time getting anything to solder/desolder.
if you wipe it on a damp rag or sponge it should be shiny.

[PCBONEZ]

Re: Please give some suggestions, I'm having a heck of time removing some caps

Sometimes the leads are bent over on the solder side of the board before the caps get soldered in. If so then once the bulk of the solder is off either straighten the leads or clip them almost flush with the board before you pull them out. (Leave a 'nub' to apply heat to.)

Fluxed solder braid sometimes does wonders for cleaning the solder out of the holes before the caps are pulled.

Biggest difference between what you are doing now and what you did before it the PCB material is thicker. You need the extra heat to heat the solder all the way through the hole. Otherwise the solder on the cap's body side is not heated and still solid. A 60 watt iron should be enough once you've gotten it down but an 80 watt might be easier to learn with. Hotter iron sounds like more potential for damage, and in some ways it is, but in another it isn't. With a hotter iron you can get on and off the board faster so heat is applied for a shorter time and it has less time to travel through the PCB material.

.

[Huckfinn]

Re: Please give some suggestions, I'm having a heck of time removing some caps

JCLA:
I have found through experience that it is very difficult but possible to desolder components from a multilayer PC board with plated through holes using consumer grade ordinary soldering and desoldering equipment. What works well is a temperature controlled high quality desoldering tool such as the ones made by Hakko, Pace and others. Hakko has a really nice quality entry level priced desoldering unit model 808-KIT/P, and they get $210.00 for it. Using anything less than that can and sometimes will work out OK, but it WILL be a challenge.

I found from trying many different units that in comparing one unit to another, you can find that a 60W rated unit is quite weak in performance while another unit rated at only 45W will work very well. This phenomenon would not make sense if you do not take into account the many other factors involved in making a really good tool for soldering/desoldering. The keys to really good units with impressive performance are a good heat path, precision temp regulation that is adjustable, and a heater element that can really pour on the power when needed with temp sensing feedback control without overshooting the set temp and delaminating or otherwise damaging the board you are working on. In this type of tool, there is no real good substitute for quality.

Huck