Month: June 2007

xv6700_diag.jpg: If you’ve been following my blog, sorely in need of updating as it is, you probably know I have a Verizon XV6700, otherwise known as an HTC Apache. In general, I love it. It’s a very capable mobile device. I use it for everything from snapping pictures when I don’t have my camera, to downloading and listening to podcasts in my car on my way to and from work. Oh — and it’s also a phone. “;->”

But I’ve had one thing that’s really annoyed me ever since I updated the ROM to run WM5: The car charger got flaky. Sometimes I would plug it in, and nothing. Even more annoying, if I had the need to do a reboot (which is rare), and the device was plugged in to the car charger, it would come up with a low battery warning, even when the battery was fully charged.

If you want the solution now, without my back-story, click here. “;->”

I finally started trying to find the answer to this a couple of days ago, and lo-and-behold, the Apache isn’t the only HTC phone to suffer from this problem. Apparently this is also a known issue with the TyTN as well, at least in the ROM dated 7/22 2006. Having found that, I checked the ROM version that Verizon is using, and it’s 2.07.20, dated 2/24/2006. Whoops!

After some more reading, I understood the issue. As it turns out, there’s a pin on the mini-USB connector on the device, which doesn’t have a use according to the standard spec, but HTC decided to get clever and use this pin to determine whether the device is connected to a data connection (computer) or not. Normally the pin is not connected to anything, and the phone’s ROM software assumes that this means that it’s connected to a PC. If, on the other hand, the pin is grounded, the phone thinks it’s connected to one of HTC’s mobile chargers.

So — the reason I couldn’t get the car charger to work properly is the fault of HTC, Verizon and myself:

  1. I’d updated the phone to the WM5-capable ROM (using a download linked from Verizon’s site).
  2. Verizon didn’t know about this issue, or chose not to deal with it.
  3. The charger that shipped with the phone is a Verizon-branded charger, not an HTC charger (which would have had the pin connected properly, I assume).
  4. HTC fixed the bug in a later version of the ROM, but Verison doesn’t have that version. (Some other carriers do though.)

One more point: The base-station and home charger don’t have this problem. The base station (I assume) has enough USB smarts for the phone to think it can talk data to it, and the home charger presumably has the pins connected so the phone will see it despite the bug.

The Solution

As it turns out, the fix is easy, if you can solder, have good eyes, and a steady hand: Just solder pin 4 to pin 5 on the phone-end of your charger, and the phone will see it again. Which are pins 4 and 5? They’re the rightmost two if you’re looking at the phone-end of the charger plug end-on, with the wide end down.

It’s easy enough to do the soldering after prying the top of the connector opened with a pair of needle-nosed pliers (being careful not to break it). If your soldering iron tip is too big to touch just the two pins — they are pretty small after all — just snip off a tiny piece of solder, place it over the two pins, and heat it up with the iron. Just look out not to add too much solder, or to connect more than just the two rightmost pins.

Here’s a nice diagram and another set of instructions to help you out. (I’ve also mirrored it here, just in case.)

After doing this, my phone charges every time. Reboots are not a problem either. I’m very pleased with the results, but less than happy that both HTC and Verizon let this get through their testing, and into the hands of end-users. I wonder how many phones they’ve replaced as a result. (The tech I talked to at Verizon’s technical support hadn’t ever heard of the problem, so either they don’t know about it, or don’t want to acknowledge it.)

Presumably this will all become moot once Verizon gets with the program and starts shipping the fixed ROM from HTC like the other carriers do. (Nudge, nudge.)

Oh, and by the way — I keep meaning to, but haven’t yet written about how I deal with podcasts on this thing. I think I’ve got just about the best mobile podcast player solution I could find, though it still has its problems. If you’re someone like Dave who’s looking for an open platform that can do the podcast thing, and do it well, Windows Mobile seems to be the way to go — not Zune, iPod or iPhone.

A moderately resourceful programmer with some .Net Mobile savvy, a willingness to utilize open source libraries, a decent business plan, and some funding could totally use WM5 (or WM6) as a platform for a best-of-breed podcast player. I mean one including all of the social networking features we geeks need, support for all of the codecs in current use, and as much cool-factor as you care to pack into the design. And it could do video, email and Web as well. Just a thought…

Pocket PC