advice on de soldering. - Page 1
Forum section: electronics / projects

author: ShadyK
author_rank: Contributor
timestamp: April 05, 2014, 08:48:23 am
content: Hi everyone. Hope every one is wellI would like some information on desoldering. Currently im doing mobile and laptop repair. I seem to be getting alot of people ask if i can change lcd connectors and usb sockets .. i know alot of people will have conflicting answers here but. What would be the best method of removing and resoldering these conponents ?? Would it be better with hot air? I no that this method can be danagerous in smallee devices where every thing is closly situated. Or would it be better to use low melt alloy (usbports)? Or is there something i am missing out? Please i would like all opinions:) or

author: N2IXK
author_rank: Frequent Contributor
timestamp: April 05, 2014, 04:17:15 pm
content: Best method I have found for removing USB or power connectors from laptop boards is to carefully cut apart the connector using a dremel tool and/or a small pair of crummy dikes, then desolder the pins individually.

author: Teledog
author_rank: Regular Contributor
timestamp: April 05, 2014, 04:50:39 pm
content: We used to use hot air for FPC connector removal, either with a workstation unit (maxed out) or a hardware store heat gun - but don't plan on re-using the connector after (typically melted).Mask off all the parts you don't want blown away with shields and Kapton tape - can never use too much & the Kapton is re-useable a few times.Clamp the board to the side of your workstation/table with the edge hanging off.Pre-heat the underside of the board a bit before working the top, and keep moving the hot air around several inches above it.Remove connector with tweezers... making sure the solder is well melted.. or you'll pull pads. It should easily slide off.A laser thermometer helps if you're scared of overheating (never past 250C).Then clean up the pads with wick & lots of (regular) flux.USB connectors can be done the same way, but make sure the tabs aren't bent around the mounting holes, or it's more of a PITA.Might want to try a few scrap boards first, until you get the hang of it. {ie: don't do it with bare feet & overheat the top, as hot components tend to fall off the bottom & leave square burn marks}

author: pa2ees
author_rank: Contributor
timestamp: April 05, 2014, 07:03:46 pm
content: I agree with Teledog, in fact, I've used such a method at work to get some nasty 50-pin connectors off. get a decent heat gun, but it doesn't have to be top of the line.another tool is a high thermal capacity soldering iron such as metcal, or an iron that can be turned way up, such as a weller. I personally love Metcal, but that's for another thread.I have gotten USB connectors outby heating the ground pins, and rocking the connector side to side, and then globbing solder over the actual leads, and rocking it back and forth. With some persistance, you can get it out, and you don't risk any damage to other chips like you do with the heat gun (all though admittedly the head gun is MUCH easier and faster).- Erik

author: chipwitch
author_rank: Frequent Contributor
timestamp: April 05, 2014, 08:07:56 pm
content: Not with laptops, but I've had success salvaging usb connectors for re-use from non-laptop boards just using a good soldering iron. Using the largest tip possible, first apply solder across the pins to short them all out. This evenly distributes the heat to all the pins. Turn your iron up to high. You don't want to apply heat too long, so hotter is better... to a point. I bought some cheapo miniature vise grips from Harbor Freight. They're about 4 or 5" long. They have just enough weight to them that if you clamp them onto a component, they will provide just the right amount of force to gently separate the component from the board the instant all 4 pads have been liquified. Of course the support tabs on connectors is sometimes a problem. Usually they're large enough to use one of the vacuum tools on beforehand.

author: ShadyK
author_rank: Contributor
timestamp: April 06, 2014, 08:14:27 pm
content: Cheers guys.i have loads of dead boards so i could just try and get them offjust for the practicethank you any ways guys..