Cant get capacitor legs out!!!

[mikay786]

Really struggling with this board, Dell XPS NVidia 790i 775, tried removing 5 caps but its been a nightmare. Ended up just pulling them out and most of the holes are blocked with fragments of the leg remaining.

Don't understand why its so hard, its like the solder around it in unmeltable.

Iron is 60w and desoldering gun is 80w

Tried adding more solder but it seems to not stick properly to old solder. When I melt it seems just like its floating on the surface of the board.

Tried putting delsoldering gun on one side and soldering iron on other end, which worked for about 3 holes but nada on the others.

Don't know what to do, contemplating trying to drill them out now with a fine bit.

Have ordered some super fine tips aswell in hope I can poke through but I doubt that will work.

[keeney123]

Re: Cant get capacitor legs out!!!

Try putting some flux on to the solder joints then tin iron and desolder.

[mikay786]

Re: Cant get capacitor legs out!!!

Have been using flux, I think my tips have had it as I didn't know about tinning the tip. Will do on the new ones ordered.

[stj]

Re: Cant get capacitor legs out!!!

400w iron is um - "impressive".
got a foto of it?

if your desoldering gun is the Duratool then it's actually about 60-70w

[mikay786]

Re: Cant get capacitor legs out!!!

oops lol sorry 400 degrees I think.

Ive got http://www.circuitspecialists.eu/csi...i-station3dlf/

60w

[stj]

Re: Cant get capacitor legs out!!!

oh those Tenma units.
i'v not heard anything good about those.
maplin was outing them for £30 a while back.

[mikay786]

Re: Cant get capacitor legs out!!!

is it fair to say these tips are dead? and probably one reason why im struggling?

[mikay786]

Re: Cant get capacitor legs out!!!

The one before that was just direct to the plug, its an improvement over that!

Id probably just break a good one but this should be fine for the odd job and to learn on. Heck I only found out about tinning tips today...

Quick question, do the duratool tip cone things need tinning too?

[stj]

Re: Cant get capacitor legs out!!!

no such thing as a dead tip.

your temp is probably too high - you should never need more than 350'
put some fresh solder on the tip and then give it a good clean with a brass wool tip cleaner.

what solder are you using?

i never need more than 310' btw.

[mikay786]

Re: Cant get capacitor legs out!!!

just some crappy one which I got in a tube, dont know what it is but I think free with iron stand I bought a while ago

ive ordered some of this stuff now

http://www.amazon.co.uk/gp/product/B...ilpage_o00_s00

[stj]

Re: Cant get capacitor legs out!!!

i hate leaded solder!

[mikay786]

Re: Cant get capacitor legs out!!!

Thought leaded was better than unleaded as is easier to work with?

[stj]

Re: Cant get capacitor legs out!!!

not if you have a temperature-controlled iron,

unleaded is only a problem for low wattage mains irons like the old Antex 15w C or 18w CS series people used to use.

[SteveNielsen]

Re: Cant get capacitor legs out!!!

I've had boards that I became impatient with and chose to use a 100w soldering gun to free the caps and clear the holes in some locations that have wide or a lot (or both) copper traces at the joint and dissipate the heat faster than a lower watt iron can provide. The tip of my 70w temp controlled iron might be hot as hell but as soon as it makes contact with such a joint the heat decreases rapidly and will take a very long time to heat the joint up if it can. The tip size makes a big difference because the greater the mass of the tip the more heat it can hold and transfer to the work.

I think you ought to be able to clear those holes with what you've got but it is going to take patience. You've got to get the entire solder joint hot enough then grab the protruding lead with tweezers or a tiny needle-nose and pull it out or poke a hot needle (like a sewing needle, pin, or safety pin of the right size) into the other side of the hole and push it out. You'll have to be very patient and use flux (don't be afraid to use a lot of flux) and fresh solder on the tip but it will eventually clear I bet. The key thing is being patient.

I don't think your tips are shot. They just need cleaning and tinning is all.

[stj]

Re: Cant get capacitor legs out!!!

IThe tip of my 70w temp controlled iron might be hot as hell but as soon as it makes contact with such a joint the heat decreases rapidly and will take a very long time to heat the joint up if it can.

that's a poor iron design.

look at what the good ones can do!
Weller WSP80:
https://www.youtube.com/watch?v=gd_8...ature=youtu.be

Chinese Hakko T12 clone:
https://www.youtube.com/watch?v=u588...ature=youtu.be

JBC C210:
https://www.youtube.com/watch?v=iyz-...ature=youtu.be

JBC C245:
https://www.youtube.com/watch?v=oTdQ...ature=youtu.be

i intend getting the T12,
those JBC irons are amazing, but the price is taking the piss.

[keeney123]

Re: Cant get capacitor legs out!!!

Lead free solder requires a higher temp. which is want is probably on the board. The tenma 60 watts soldering iron is what the input power is. The iron maybe is 40 watts. If your board has multiply layers than you will need way more wattage. 100 watts is not unreasonable because all those planes with-in the board have to be heated at the same time. I have seen irons that are capable of 270 watts for a limited time. Of course the wattage may also be dependent on the tip. Small tip area the wattage can keep up. Larger tip area requires more wattage to heat that area. My opinion is the Metcal station is safest iron to use as it determines magnetically what the material that is being solder and adjust for that material so the board will not be burned by to hot of an iron for to long.

[stj]

Re: Cant get capacitor legs out!!!

the tenma has slow response and recovery, that's the problem with them.

[keeney123]

Re: Cant get capacitor legs out!!!

As a Professor on Electrical Engineering told me once wattage is what determines the power required to heat the joint. Wattage is power. One can use the formula F= M*A to confirm this.

[c_hegge]

Re: Cant get capacitor legs out!!!

your temp is probably too high - you should never need more than 350'

You may not need higher than 350, but going higher shouldn't make it any harder to solder. I have mine cranked up all the way to 500*C, and I've never had issues.

[stj]

Re: Cant get capacitor legs out!!!

i as refering to the oxidised blue tips.
if your temp is too high the flux burns and the tips need cleaning.