Wednesday, May 27, 2009

Money Lost

T-Money, that is. I wrote about this special device that is used for subway and bus fares (some taxi's reportely will accept it, too) back two years ago. Well, yesterday this two-year old widget (it attaches to your cell phone) broke. It wasn't visibly broken, it just refused to work. I took it to the station clerk, and he tried it on his machines, and confirmed that it was dead.

You know what's coming... Engineer, broken electronics item... You guessed it. I dismantled the thing to see what's inside.

Here is the main brain. Attached to a wire loop antenna and what I'm guessing is an inductor used for impedance matching.

The cool thing is that I could see immediately what was wrong. One of the antenna wires had come unsoldered. I think I know why it broke, too. You'll notice there is a small pocket in the body of the plastic case, which is where the electronics should be located. In fact, it looks like there was some adhesive holding it down. I say was, because when I opened up this unit, the whole thing was rotated slightly, so that the electronics was at the edge, or slightly outside of that pocket. I believe the resulting stress broke off the antenna wire. I simply soldered it back, and hopefully it will work and I won't lose the $6 or so remaining value.

I'll test it tonight and report back.

EDIT: It works! All those years of Engineering school finally paid off!


The Stumbling Mom said...

BRAVO! It will work, I'm sure. This is why I sent you to GA Tech! More people should try things like this. It was so simple, but if you hadn't done it, the little device would have been thrown out, your money lost, and more plastic added to the garbage dump.

John said...

You should advertise this service on Korea Craigslist (Claiksrist?) or better yet, offer to pay W1 for any of them that are broken, then fix them and transfer the cash to your account!