Question on hardware problem with my original GTA01 phone

Gary Oliver go at l5.org
Tue Jul 22 20:16:30 CEST 2008


Shortly after I received my original GTA01, it developed a problem where 
it won't run (i.e. powers off abruptly) when plugged into a USB port and 
enumerated (i.e if I plug it into a USB port with no 'driver' on the 
host side, nothing happens.)  I suspect it has something to do with the 
charging circuit shutting off power somehow, since a charged battery (I 
have a spare that is still charged and can charge reliably on my new FR) 
runs the unit fine until I plug into the USB.

The problem is that this failure prevents me from doing any kind of 
flashing of the software - assuming it might be a software bug - since 
presence of USB stops the unit cold.  I *have* a debug board, but have 
been, so far, unable to do anything with it that resembles 'debugging'.  
It's likely caused by the older Debian I'm running on my main 
development machine, but nevertheless, using the debug board seems 
problematic at this point. (I do a lot of embedded stuff in my 'day' 
job, much of it under Linux, so I'm not a novice at ICE or debug pods, 
but, as I said, the difficulties are likely due to 'libraryitis' on my 
old system - I haven't tried the tools on a more recent Ubuntu 8.04, 
which is what I'm using for most work these days.)

So, the questions are:

1) Is this likely a hardware failure and if so, can someone point me to 
the component that needs replacing?  I do have appropriate surface mount 
rework tools, hot air and such, so can perform basic rework (no BGAs 
please).

2) Is there any way to bypass this feature (e.g. running the USB 
connection to the Neo by inhibiting the power connection?)


By the way, this problem originally showed up after the unit had sat for 
a lengthy time on the USB port 'charging'.  I never had the 'loud buzz' 
problem some have mentioned.  It just stopped working.  Unfortunately, 
while using the debug board for power injection, I attempted to flash 
the software sometime after the problem arose and the unit decided to 
summarily power off during the rootfs flash, and has been the same ever 
since.  The debug board power injection doesn't seem to help anymore.  I 
was running the original uboot (came with the unit or was initially 
flashed just after receiving it - I don't remember) at the time of the 
failure.  I WAS able to flash a new uboot (at least new at the time) and 
that had no effect.

So if anyone can peek at the schematics for GTA01 and let me know if 
this sounds like a simple fix, I'd like to get my old Neo up and running 
again, for nostalgia, if nothing else.

-Gary





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