For a project I am working with the Huawei E970 and B970 devices installing openwrt onto them. (see:
http://wiki.openwrt.org/toh/huawei/e970
At one point I had somewhat bricked the device and needed access to the CFE bootloader. Requiring me to solder a USB to TTL Serial Cable onto the motherboard.
The pictures on
openwrt were somewhat useful giving me at least an indication of where the solder points were.
One thing to note is that the ground pin isn't special that just happened to be a convenient place that was easy to solder to.
Hopefully these ones will provide a more detailed view for someone who may end up in the same position!
