Recapping a video card...strange solder behavior

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Xaero_toast

Limp Gawd
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Dec 29, 2008
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I am not an expert at electronics soldering. What I've learned, I've picked up online (here, and badcaps.net), or figured out by trial and error.

I have had some good results replacing bad caps on a variety of items. Three or four tivo power supplies, a handful of flatscreen monitors, a motherboard, and today I'm working on a video card. It's actually kind of fun, especially when you get nice broken electronics for free and fix it with less than $10 of capacitors.

This video card is an XFX Geforce 8600 GT. It's demonstrating a behavior I haven't seen before. The solder wants to follow the iron when I pull it away, leaving an insufficient amount of solder behind on the capacitor legs. What am I doing wrong?
 
i am no expert for sure nor do i know best practices for soldering small electronics like this, but do you put flex on the cap legs? and clean your tip well?
 
Well, first off, make sure the tip on the iron is clean and well tinned. The thin layer of molten solder is what will transfer the heat to your component, a dry iron doesn't work anywhere near as well.

You can flux the board if you like, but you're probably using rosin core solder, which includes a decent amount of flux in it already.

When soldering a through-hole component, insert all legs of the component, then flip the board and place the tip of your solder wire at the intersection of the leg and the board. Touch the iron to the leg ABOVE the solder (not touching it) and allow the leg to get hot enough that the solder melts and wicks onto it.
 
It's likely that if the solder is following the iron that the joint is not hot enough, graphics cards, and motherboards have many many layers and huge low impedance ground planes which can sometimes require a lot of extra energy to heat up. Try and leave the soldering iron on the pad and lead for a little longer than usual and see if the solder flows better. Also aways use solder with flux and if neccesary use extra flux. If you don't have enough flux solder doesn't flow very well. Another tip is to try and make sure that you suck up all the old solder. Due to new electronics being RoHS certified they use lead free solder, and that can create a mess if you mix leaded solder with it.
 
Flak is correct. If the solder isn't attaching then the joint isn't sufficiently heated.

Always put the iron on the joint you want to solder and let the iron heat it up for a good time and then put the solder on. Flux is good but really the solder should just attach if the joint is hot enough.
 
Extra flux helped. I also set the iron hotter. I had it at about 750, turns out it maxes out at 840.

The few joints that gave this trouble were also difficult to desolder. I think I may have burnt them just a bit on the top, which really didn't help.

Turns out my efforts may be for naught. I blew the dust out of the fan before reattaching the hsf, and the plastic fan blade cracked in half. I'm not having great results searching for a replacement fan, and the card itself does not have sufficient worth to justify a whole new cooler.
 
I hate XFX's shady lifetime warranty all over again. They wouldn't honor it last time the capacitors died, and I held on to the card thinking I'd recap it someday when I had time, and a use for it. Now it's recapped, but the fan is broke. That's twice failures that should have been warrantable...

It does work. The card runs, with a heatsink borrowed from another card. Now if I can just find a replacement fan to fit the dang thing...

Thanks for the feedback!
 
why wouldnt they honor the warranty? I owned an XFX along time ago but never made a claim?
 
At that time, the cards were advertised with "lifetime warranty". I don' think they do that anymore.

However, you had to register it online with them within a short period of time (maybe 30 days) for it to be valid, or the lifetime warranty was reduced (to either 1 or 2 years, I don't remember which). The unfair part is that the warranty was advertised as "lifetime", but the need to register in order to receive such warranty was not printed on the box or any of the literature that came with the product.
 
Xaero_toast said:
I am not an expert at electronics soldering. What I've learned, I've picked up online (here, and badcaps.net), or figured out by trial and error.

I have had some good results replacing bad caps on a variety of items. Three or four tivo power supplies, a handful of flatscreen monitors, a motherboard, and today I'm working on a video card. It's actually kind of fun, especially when you get nice broken electronics for free and fix it with less than $10 of capacitors.

This video card is an XFX Geforce 8600 GT. It's demonstrating a behavior I haven't seen before. The solder wants to follow the iron when I pull it away, leaving an insufficient amount of solder behind on the capacitor legs. What am I doing wrong?
Click to expand...

The problem is lead free solder. Lead free solder doesn't flow was well as lead solder. So you'll need better flux and more heat. You also want to make sure you're using the right type of type for the job. Not every solder tip is created equal. If you're doing surface mount capacitor you want a small flat chisel tip, that will give heat across most of the component and pad.

If you're doing where I work we've changed some on 7300GTs. Another way I use is a heat gun with a conjunction the soldering iron. I put solder on it the lead, and heat the area up with the heat gun. Then hold the soldering on the pad and the lead, the solder will usually flow better then.

Another good idea is to desolder the lead free solder thats there. Then resolder it. Just FYI anything advertised as ROHS its going to use lead free solder. So pretty much any and call computer components you mess with will be lead free.
 
This has happened to me when trying to solder when the pads have not had the solder sufficiently cleaned, the old solder percentages must not mix well with the new solder (ie. lead free).
 
I thought I had nothing to lose, so I went back through their support website and reported the fan failure, despite the fact they declined to service the card a few years ago when the capacitors failed. There is supposed to be a replacement fan coming in the mail now. I will wait and see what happens.
 
I have to give credit where credit is due. They made good on the warranty the second time, and sent me a new fan/heatsink assembly when the fan broke on the old one.
 
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