[Tilt, TyTN II, MDA Vario III General] jgmdean:
Guessing here...

OK, so I have a vested interest here since I have a 181007(RC01)/US ATT Tilt. In the 3 weeks I've had it I've done quite a bit of software hackery and graduated to flashing after I lost patience with the ATT ROM image. I'm happily running Dutty's latest since he does a much better job of putting a ROM image together than I do, plus I don't have the time. I *did* flash my own boot screen to something pleasant plus my name and phone number so I don't have to look at the Death Star on every reset. :p My day job includes being a systems troubleshooter, so I'm going to give my best analysis and speculation here:

Firstly: no matter the ROM image, if you don't have the "Battery Status" Today Screen plugin, GET IT NOW!

One of the nifty bits of information BS can display is the power consumption of the device in either mW or mA. What I've noticed is this: The Kaiser/Tilt/Tytn II/whatever's power consumption varies wildly, I've seen it as high as 800mA with all three radios on and in use and with the CPU 100% busy. (No I'm not going into how I set up that stress test... :rolleyes:) The point here is that the power management system is nicely designed and does what I'd expect: Any external power is "used" to power the device first and anything left over charges the battery. This is why the device has a 1A charger, it's possible for the device to draw more than a 500mA supply can deliver so it's actually draining the battery while plugged in, albeit at a much slower rate. If we add into this mix a (possibly date triggered) runaway software bug that jacks the power up this could explain why some people's batteries were drained while supposedly "on charge", especially if it happens when you might not notice until too late, say overnight.

Now if we add a manufacturing defect/weakness into the mix it gets more interesting. These kinds of things are unlikely to fail completely in all cases (e.g. bad mini-usb socket contact). When that happens it can drop the actual power making it into the device down below the charging level. In that case if the software bug bites or a backup is scheduled or whatever the device will drain the battery and will refuse to turn on with a red light if there isn't enough juice. The other thing that can happen is that the intermittent fault can heat up or otherwise degrade the bad connection to the point where it fails completely. As noted here the power system is designed such that it won't power on unless a battery is present and if the fault happens "downstream" of that detection as far as the device is concerned it has no external power and drains the battery, but will start with a charged battery but can't charrge it. If it fail "upstream" then the device will think that there is no battery inserted and will not turn on with a red light (which eventually will fail as well when the battery is completely drained, but that might take a while as that circuit is most likely VERY low power.

I think these two problems (software power consumption bug and hardware power path failure) in various combinations and timing can explain the multiple failure modes that have been reported here.

I'm sure someone from HTC could look at the serial numbers of the failed units and see if they all come from the same run or batch of components. I hope they do that and then do the Right Thing and issue a recall for the affected serial numbers. :cool:

James