Cell phone connector fix

My good friend James contacted me with an electronics problem.  Seems his daughter’s cell phone was on the fritz.  So I agreed to take a look.

She has a Pantech P7000 flip phone, but it stopped charging.  I asked a few questions first to understand the nature of the problem.  For instance:

  • Has she tried other wall chargers? Yes, all give same symptoms.
  • Has she tried other batteries? Unknown.
  • Has she tried wiggling the cable to see if it makes connection? Yes, and it does.

James gave me some great info, so I knew what I was in for.  My guess was that the charging connector on the phone was going bad.  I’ve seen it before.  James sent it to me to have a look:

The first thing I did was have a look at the charger, just to test out the verbal info I gathered from James.  With a set of helping hands, I probed out the power and ground pins:

charger cable connector

I saw a nice steady +5V, so the charger was good.  Although its plastic shell was a bit wobbly, it seemed to be functional still.  Now, onto tearing apart the phone.

I couldn’t find a tear-down guide online, so I had to figure it out for myself.  There’s one obvious screw above the battery compartment:

reverse without battery

But I had a hard time finding the other hidden screws.  Turns out, there are four hiding underneath a bezel surrounding the keyboard:


Once those are gone, the assembly comes apart rather easily:

Now the back shell can be removed.  When I did, the charging connector tumbled right out.  So it was no longer even attached to the PCB:

connector gone

Here is a closeup of the connector:

bottom side

You can even make out the copper pads still attached to the pins, which have ripped off of the PCB.  That’s never a good thing!  This type of damage is actually quite common in consumer electronics.  This interface isn’t always well designed on most cheaply produced gizmos.  And yet, it’s an area that is very high-traffic; in other words, the mating cycles of the charger or serial cable to the phone is always quite high.  As a designer, I would prefer these interfaces to be more robust.  But then, I’m more interested in lifespan of my electronics, whereas most electronics companies would prefer you buy new products every 6 months.  I digress.

At this point, I wasn’t yet sure I could repair this.  There was significant damage to the PCB pads (some pads entirely gone!), so I first cleaned off the remaining pads by re-tinning 1:

damaged pads

Next, I cleaned off the pins of the connector.  Then I re-placed the connector down on the board and soldered it back on.  I got maybe 80% coverage of pins to pads.  The number of pins on this connector is maybe 10-12; obviously only 2-4 of which are used for the power charger.  So all that was strictly necessary were those sets of pins.  As luck would have it, those power pins were still intact.  The phone is back to life!


Full Project Gallery:

iPod jukebox (phase 2): prototype

You remember the first phase of the iPod jukebox, yes? To jog your memory, the basic goal was simple. How do I make these dust-collecting components:

…work with my iPhone in order to have music in my workshop?  Simple concept, not so simple electronics. The project is mostly a connectivity issue, i.e., there are tons of inputs and outputs that must all be managed with connectors and wiring and power regulation.

On paper, the system looks something like this:

system schematic

In Phase 1, I had done a substantial amount of wasted work with one such cable: the audio/power cable for a first & second gen iPod.  Since the project had been shelved so long, several generations of iPods and now iPhones have come and gone.  Well, in that time, Apple has settled on USB as their power bus of choice, rather than FireWire.  Thus, I had to likewise change directions on this project to accommodate my iPhone (rather than the antiquated iPods).  Mounting options naturally have to change as well.  And the overall enclosure gets modified too.  It’s quite a ripple effect when your central component (the music player!) gets the switch-aroo.

I was locked in a brain-freeze for quite a while on this part, the mounting and enclosure.  I had been stuck on the idea of trying to make a “pretty” Apple-esque Plexi box.  But I finally admitted to myself that this is just above my skill set.  I have a hard enough time making ugly black plastic kit boxes look pretty, let alone clear Plexi where blemishes show so easily.

So instead, I’ve decided to embrace ugly.  Why not just make this phase of the project an intermediate step rather than the final step?  My garage is already an acceptable and appropriately dirty place, as is the attached workshop.  Just let this jukebox fit in with that kind of environment.

So I completely re-thought the enclosure phase.  I began cobbling together other old cases, car mounts, and such to make a quick enclosure that would be practical, yet secure.  Such parts included:


iPhone gooseneck holder iPhone holder #2


USB audio iPhone cable


USB Car Charger for iPod charging circuit

In putting all these items together, it now (unintentionally, I assure you) might resemble something else entirely, as you’ll see in the project gallery below 1.  But hey, this jukebox does reside in the man-cave after all.

What’s in store for Phase 3?  Coming soon, I’ll package all this mess a little nicer.  I have some connections in the machine shop world.  I also will reveal this gizmo’s name, so stay tuned.

Project Gallery:



IKEA mini-kitchen mods

One of my daughter’s most beloved toys is her IKEA DUKTIG mini-kitchen. It was a gift from the grandparents, and it’s one that she’s never tired of. Iris is a lot like her mommy, and baking and cooking wonderful savory foods are some of the many things they love to do.

The only problem with her mini kitchen is that it lacked a few fundamental similarities to Mommy’s big kitchen. For instance, her little oven door opened the wrong way. And there was no light in the oven that came on when she opened the door. This was just no good. Time to get modding.

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