need help soldering very tiny component

Discussion in 'General Electronics Chat' started by NTkiller, Nov 8, 2013.

  1. NTkiller

    Thread Starter New Member

    Aug 6, 2013
    Hi, I am trying to replace the usb port on my phone. It is a Motorola Droid X, and it's had a hard life. Before I got it, it had been faceplanted, busting both the screen and the touch sensor. I got it for free, and put a screen and touch digitizer in it and it works perfect. Now I am having problems charging, and Ive been going through cable after cable, so I know it is the port in the phone that is worn out. Here's the problem: This is a VERY tiny part to be soldering on. As you can see in the pictures, the connector itself has a small piece of metal hanging over the usb pins. How would I solder those on the new connector, since it would be near impossible to reach with a soldering iron? I've already devised a way to remove the old connector. I read this from somewhere else on the web, but you are supossed to cover the rest of the motherboard in thin masking tape (to keep metal shards from falling into places where it could short out something), and then take a dremel with the tiniest cutoff wheel you can find, and cut it off the board. Then you take soldering braid and unsolder the remains. Comments? Suggestions? Or should I go look for a new motherboard, or worse, a new phone:(?
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  2. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    To repair that properly will require a hot air soldering iron at the least or a reflow oven.

    As you are a "newbie" (no offense) its now trash.. That type of repair takes skills.
    Replace the whole board or buy a new phone.
    mobileman likes this.
  3. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    Don't put a dremmel to this, you will cut the lands you need.

    A hot air reflow iron will heat the board to remove the broken connectors and then let you place down a replacement.

    Do you have a replacement? There are 100's r even 1,000's of these connectors, and finding the one they used is no small task.

    It is repairable if you have the parts and the tools. Technique is also needed but maybe you'll get lucky.
  4. NTkiller

    Thread Starter New Member

    Aug 6, 2013
    I've done some work before with soldering before, but nothing this small. I've gotten close though. I soldered a tiny smd power switch using only a soldering iron and some soldering wick. so how would one solder one of these on without a rework station? I really don't want to get rid of this phone because the usb port is broken. And while I am in the phone I am probably going to do the wireless charging mod (so I don't have to plug up the phone every time I need to charge it). Any comments?
  5. DerStrom8

    Well-Known Member

    Feb 20, 2011
    You can get soldering iron tips small enough to do this type of soldering. For desoldering the USB connector I suggest using copper braided wire (Desoldering Wick) and a fine-tipped adjustable-temperature solder iron. While a hot-air station would probably be the most effective, I would think it would be easier (and cheaper) to do it by hand for someone in your position.
  6. tcmtech

    Well-Known Member

    Nov 4, 2013
    I have done a few tiny repair jobs like yours before but not on cell phones.

    My trick was to use a small pencil type soldering gun with the tip filed down to a near needle point. I used that to melt the solder and then blew it off with a canned air straw then did the part pick and placing with a set of needle tweezers.

    If you have a magnifying glass it helps. Having patience and something else tiny to practice on first helps even more!

    All said and done I hate doing tiny surface mount repair work. :p
    killivolt likes this.
  7. BReeves


    Nov 24, 2012
    You have been told two truths..

    1. Make sure you have a replacement part.
    2. You really need a hot air station to remove it without damaging something.

    You can get a cheap Hot air station off eBay. ~$50.00.
  8. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    If I was to attempt this without hot air I would try this:

    Heat the large side tabs first to get the part itself off. Solder wick may help. Try not to lift the pads.

    Once I have 4 pads in daylight I'd flood the 4 very tiny pins to get all 4 (5?) to release at the same time. Lift off part and dispose.

    Next, wick off any remaining solder.

    Place fresh part, make sure tiny lead are aligned then solder large pads.

    Now for the tiny pads: Just solder as one, then either tap the board hard to make the excess solder fly off (do watch you don't make other shorts), or try solder wick to unshort the small pins.
  9. killivolt

    Active Member

    Jan 10, 2010
    I'd never considered a can of air and blow the solder off. I'll remember that one.

    I used to do repairs and set the board on a full pot and remove the part, clean with braid and float solder surface mount components. It's tricky, I used water Soluble Flux it was easier to work with as long as it was fresh.

    I'm guessing the other side of the board is ground plane. It should be simple to heat the area, the problem comes when other components get hot and you knock of a capacitor or resistor while trying to remove the connector.

    My suggestion is find another phone to practice on, tear it apart and see if you can place the edge of the board on a hot plate of the stove and then use tweezers and remove the component. Get some water soluble flux once removed you will know the heat required to melt the solder + you will have gained the skill. Re-flux the area and put the connector back on and heat it back up.
  10. NTkiller

    Thread Starter New Member

    Aug 6, 2013
    Well, I managed to pull it off. I got the replacement port in yesterday and I put it in this morning. What I did is I took the phone apart and took out the motherboard, then I taped the motherboard to my work surface. I covered the motherboard completely with tape to protect the other components from the carnage I was about to unleash. I then took the dremel and cut the mounting leads off. The connector simply fell apart after I did that. Next, I pried the rest of the metal pieces away from the connector. I then took the soldering iron and removed the inner header of the connector and the metal remnants of the connector still soldered to the board. After that, I took soldering braid and cleaned up all the pads on the board. Once that was done, I took the new connector an cut a notch over the pins so I could get to them to solder them. I then tacked one of the mounts down, and moved the connector around till the pins were lined up. I then soldered all the mounts on, and flooded the pins with solder. I then took the braid and wicked away the excess solder. After trying to unbridge a few pins, and disassembling and reassembling the phone several times, I finally got it. Man, was that a pain in the neck!!!!:mad: But it worked:D
    ErnieM and shortbus like this.
  11. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    Whatever is, is right.

    Good job, congratulations!