Failed DC jack repair. Oopsie

[MrBojangles]

So we're dealing with a broken tip on the DC jack. I'm trying for an hour to desolder the old DC jack but it just won't come off. I start using a little force and part of the board gets broken. It's not pretty at this point.

Anyway I try to solder on the new jack but it goes so-so. I install the motherboard again and I'm getting smoke and all kinds of trouble. NOW. I'm gonna desolder the DC jack and try to clean everything and go again. What I'm wondering is, do I need to resolder all the points? What's the minimum solder contact points I need for it to work? All of them? Any advice is appreciated.

Imgur link: http://imgur.com/GZfXEBZ

 

[NYJimbo]

LOL.

 

[NviGate Systems]

Smoke? Time for a new MB. More likely it is toast. Especially if parts are broken.

 

[Larry Sabo]

I'm gonna desolder the DC jack and try to clean everything and go again.

Could you post a picture of the MB with the jack removed and the solder cleaned up? The picture you posted is of no help because it's not clear or close up enough. NEVER, apply force to remove something you're unsoldering or you will rip traces off the MB. If that happened, time for a new motherboard. Did you use hot air or soldering iron? Flux? Bismuth?

I would suggest practicing on scrap MBs until all goes well and looks professional every time.

 

[kwest]

This happened to me once but the mmtherboard bent and cracked a little. Ended up up buying the client a new motherboard and they just paid the original quote for D.C. Jack repair.

 

[jbradt]

I was always told that once the smoke escapes, the magic is gone.

I agree with replacing the mobo. Chalk it up to a learning experience and eat the cost.

 

[symbatech]

+1 for never using force when unsoldering a part. If you get a particularly stubborn part, sometimes preheating the area with a hair dryer or heat gun can give you an advantage. Just be sure not to melt any plastic parts, and make sure you ground the board and yourself while you are working on it. If you still cannot get the solder joints to flow enough to remove the part, you can try a second soldering iron from the top of the board if it's accessible. Or try a higher wattage iron.

If you do destroy the pads and/or traces it is possible to repair them, but unless you are very comfortable with soldering you're probably further ahead just replacing the board. Smoke indicates a direct short and there's a very good chance you fried other components on the board, so replacement is your likely best option at this point.

 

[PC Doctor]

I am presuming from the photo you have snapped the thin sliver of the board off down the side of the jack, presume this is a Samsung laptop?

The 2 solder points down that side are earth points and used more as mounting points, they don't actually run any power lines and are more there to give the jack port some stability. You can actually run the machine without that bit attached and it will work fine (I have snapped more than one) I have re-soldered the jack on, pushed the broken piece back on the 2 jack legs and then soldered that.

The worrying part is the smoke, that normally means that you have soldered across a joint and joined pos / neg together, at that point the board could be toast. De-solder what you have fitted and clean everything up with some wick then try again as you have nothing to lose now anyway you may already be into a replacement board, doing it again may salvage it.

For future reference, use some snips to snip the centre out of the port, remove all the plastic and then snip the metal pins, snip the jack outer case in half and fold outwards then you can snip the legs and remove. You now have just the legs to desolder, buy yourself a heated solder sucker and some 1mm solder with a flux centre and the solder will flow easier and the sucker will take it all away in one go.

 

[Krynn72]

I'm trying for an hour to desolder the old DC jack but it just won't come off.

Whatever you're doing, its wrong. Desoldering that jack should take 10 mins if you're being absurdly cautious. An hour, even if its an exaggeration, is crazy. I'd recommend you buy a new, higher quality soldering iron, and chipquick flux and low melt solder. Its probably just a tools issue, because I remember when starting out I had a lot of trouble desoldering stuff and it was just because I was using bad equipment.

Anyways, at this point, just replace the board. No amount of replacing the dc jack will fix whatever got shorted and burned up. You now need a schematic and component level troubleshooting skills.

 

[glennd]

I did a few of these before I realised a better approach is to cut the legs of the jack first, get the jack out of the way, then you can remove the remaining bits of the legs from the board one at a time and much faster because the jack is no longer drawing the heat away.

The right tools for the job as @Krynn72 points out. I also use a solder sucker and solder braid to help clear the old solder away.

Edit: I realise I just repeated what @PC Doctor said. I might also add that desoldering is an art that you should practice a lot before attacking customer machines.

 

[NYJimbo]

So what did you end up doing with this one ?

 

[MrBojangles]

So what did you end up doing with this one ?

I haven't done anything more but Ill try to redo it and see if I can make it better.

 

[Altster]

To the OP, practice, practice, practice on other electronic circuits until you can do this with your eyes close (not really, but I think you know what I mean.) If you cannot do this in a timely manner, then DON'T! Either quote a replacement motherboard or find someone to send it out to have it replaced (who would also provide a warranty TO YOU for the work done.)

I quit doing solder work because I am too nervous and know for a fact that I would screw things up. If I need solder work done I let my partner (in crime) do it - he's younger and has better eyesight as well.

 

[cam w]

When desoldering a liberal amount of flux is essential !

 

[NviGate Systems]

Also remember that ASUS and others use horrible lead free solder that can require up to 850 degrees to get it soft if you don't mix it with leaded before removing. You also can't play with it for long or the solder won't respond to those temps, I don't know what the technical name is, but I have experienced it. You mix the solder in and work hard at it but eventually it doesn't melt unless you pour more heat and leaded solder with flux, it's like it "cures" and won't budge.

 

[brandonkick]

Wow....

Never use force when desoldering. You can apply a TINY bit of pressure with something like an exacto knife when trying to lift something like a chip with many legs on it... but force wasn't necessary here.

A hot air gun would have made quick work of this. Apply some new fresh solder first to the legs, then hit it with the hot air and easily pull the chip away. Then use a solder sucker, desoldering iron, or desoldering braid to clean the holes and easily slip the new part in.

This board is ready for the trash bin. Might as well use it to practice your soldering skills. Practice removing and reinstalling different capacitors, chips and so on around the board until you get comfortable with it. Try using hot air. Short answer is your looking at buying a replacement board for this customer.

 

[AML]

+ 1 on the hot air gun.... and never force it...

 

[mikeroq]

We don't even bother with replacing jacks that are on the motherboard anymore. If it's not on a cable or a separate board we replace the motherboard.

Hot air guns are nice.
Sounds like your soldering iron doesn't get hot enough.

 

[PR Tech]

+1 for ChipQuik-SMD-1 Solder Removal Kit.

 

[PC Doctor]

We don't even bother with replacing jacks that are on the motherboard anymore. If it's not on a cable or a separate board we replace the motherboard.

Hot air guns are nice.
Sounds like your soldering iron doesn't get hot enough.

Sounds like an expensive way of doing things for a part that is a few quid