Replacing Caps

[kryptobs2000]

Whats the best method to unsolder and replace caps. I know that I'm gonna be told it's best to just run them in parralell but I'd rather not do that as I try and make my mods look as neat as possible, and even if I were to do that I'd still like to know the best way to remove caps so I can take em off dead mobos/videocards without messing up the pcb (and my soldering iron). What wattage iron do you use umm.. just w/e... lemme know how you think it's best done. :)

[craig588]

Solder sucker and a 45 watt iron. Tin the tip of the iron a bit so you can get a bit more surface area on the leg of the cap. (The hot solder will flow to the cold solder on the cap automatically) Once you can wiggle the cap around and see the leg move hit it with the solder sucker. Do the same for the oher leg. The cap probably will still stick in there because a little bit of solder probably got left behind, you can push on the legs with something hard, I use 4cm*4cm square ceramic tiles, and it will come out.

[kryptobs2000]

Thanks alot, great explanation :) :toast:

edit: This is a solder sucker right? http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F011%5F009%5F007%5F004&product%5Fid=64%2D2098

And can you explain how it works? Like after it sucks up the solder, where does the solder go :confused: lol, do I have to replace it after awhile after it's full of solder or can it be emptied or what?

[craig588]

Thats one of the cheaper ones, but I think even with a cheap one like that you can unscrew the top and empty it out. The difference between a cheap and high end one is like 10$, I would just find a good one. The high end ones don't have a handle that shoots back when you push the button which causes the inevitable face brusing. They have a longer vacuum duration too.

Solder just sits inside it, it's not insulated or anything because there is such a small amount of solder pulled in that it cools almost instantly. They are very simple, it's basicly a spring that locks and when you push the button it releases the spring, allowing it to expand to its full height, the top of the spring is connected to a plate with a seal which creates a vacuum when it goes up.

Edit: haha, radioshack is a rip off, here is the exact one I have that I paid ~16$ for at radio shack a few years ago. http://www.allelectronics.com/cgi-bin/category.cgi?item=SSR-1
From one of my favorite electronics web sites too, it's not just some random unreliable link.

[cirthix]

i use a crappy 30w radioshack iron (it was cheap...). what i do is heat one leg of the cap, from the back of the pcb, then lever it out gently. once it moves a mm or two, repeat the process on the other leg. repeat untill its out. to add a cap, bend the pins to fit properly in the holes, put a small dot of solder onto the tip of the iron, and heat each solderpad for a second or two before switching to the other. this melts both pads at once and allows you to easily wiggle it in. once its in, put a dot of solder around each leg and solderpad, to make sure it has good contact.

[angrysquirrel]

I've always used coper braid solder-wick on the backside of the pcb for removing things. I've never done it on anything like a videocard or mobo, though. So I'm not sure if it's safe for a pcb with many layers of traces.