repairing lifted circuit board pads

Discussion in 'General Electronics Chat' started by jaybuff, Feb 10, 2012.

  1. jaybuff

    Thread Starter New Member

    Feb 10, 2012

    I am attempting to repair the micro-usb connected that broke off my HTC Evo 4g mobile phone. When I opened it to look at the damage I discovered that the three inner pads have almost completely been lifted off the circuit board. The two outer pads look to be in good shape. Here are some pictures of what I'm working with:

    After cleaning the area I wasn't able to locate any of the traces. I have some copper tape that I was hoping to be able to use to replace the pads, but I don't know what it would even connect to.

    I'm using this replacement connector that I bought from mouser from mouser:

    Any advice on how I can repair this would be a great help.

  2. evilclem


    Dec 20, 2011
    Only way to repair that is if you know where the tracks go. I can't see any at all on the photos. If someone at work bought that to me, I'd tell them to buy a new phone.
  3. luvv


    May 26, 2011

    It looks like there is a some small bits of remaining pad/trace left .

    You could attempt to use this product to prep the areas for solder.

    Not saying it would work, but if you clean the area being careful not to remove the remaining bits of pad then flood the area w/ several layers maybe..just maybe.

    Good luck,

  4. smellofburningtantalum

    New Member

    Feb 12, 2012
    I assume that you are as tenacious as me when it comes to repairing damaged items!
    It looks, from the pics, that the track from the pads extends out under the lacquer resist (rather than disappearing down a PTH hole onto another layer) I would have a go at scraping the green lacquer CAREFULLY to reveal the copper track underneath. My experience of this, over the last 40 years, is that the best tool is a medical scalpel- the type with a curved cutting face. Hopefully, once the track is uncovered you can solder some tails of BTC (showing my age!) fine tinned copper wire, and I would face these away from the connector so that they can be 'folded' over the return to be soldered to the SMD pins on the new USB connector. This will give a bit of strain relief to the setup. I would slightly straighten the pins on the new connector so that they are off the PCB when fitted, then solder the wires to the relevant pins. Even with 'young' eyes I would get one of those head-mounted magnifier gizmos for this job, and a fine-point bit in the iron (hate them for most jobs...).
    Incidentally- If you need to remove a connector like this, the best way to achieve it without damaging the track pads is to use a Dremel-type tool with a fine fibre cutting disc to cut through the mounting frame so that it is in at least two parts, then cut across the pins too. This makes it relatively easy to unsolder the pins individually to remove them, and the frame tags can also be removed with the aid of a good quality solder sucker (there are some junk ones around with the orifice being far too big...)
    Hope that this is of some use. Good Luck! SOBT.
    soldertools likes this.
  5. zaw

    New Member

    Feb 13, 2012
    I have done repair on cell phone like that before. Mine was an LG and I was only able to track down only two of the USB traces that were on top layer. Other traces went underground.

    I salvaged connector from different FUBAR phone. I scraped the protected layer with tip of new razor blade (I don't have fancy tools like Smellofburningtantalum). I used some wires from motor windings, they are coated. scrape the coating and tin, also tin the traces on circuit board and solder. Apply 5v and thing powered up! now I have dangling USB port. With nothing to attach to.

    End up using 5min epoxy and glue the USB connector to PCB. Modify the plastic to fit the USB port. Used the phone for like 6+ months.