What does it mean when I ring a 137x number and get an "out of service" message, yet ringing the same number a few minutes later gives a "power off" message? I thought the two would be mutually exclusive i.e one meaning the SIM card has expired, the other the SIM is valid but the phone is currently switched off.

Been trying every few days for the last few weeks with the same results. Trying my old expired 136x SIM number reliably gives the "out of service" message.

BTW anyone know the pinyin versions of those messages? All I can make out is "dui4 bu qi2" and "dian4 hua4"

The short answer is the Chinese network has a lot of bugs. I know because it is my job to test such things....

STOP here unless you want to die of boredom.

You asked for it.....

It depends on how the Phone was switched off, when a phone is powered down it it send a message to the network to say so i.e. "the subscriber is power off now", however if the battery has been removed whilst the phone is on then you should be "out of service" because the network can not locate your phone and does not know what has happened to it.

However their is also a timer set by the network that tells your phone how often to "update" the network with your location (which incidentally is why if you leave your phone near a radio you will hear the "update" happen every so often).

If this has happened once then the phone was powered off and then the timer expired between your two calls.

Sometimes if the balance is below zero, they would say " out of service ", or when the signal is not so good over there.

"Power off" means network has received power off message from mobile before, which a mobile usually does to detach from the network when you switch off the phone.

"Out of service" means network can not reach the mobile. There are a few causes behind this, for instance, no coverage or mobile accidentally out of power.

Sometimes people removes the battery instead of switching off mobile to create an "gloss" that he is in no or poor coverage, so that his boss would not bother him over weekend.

both the character&the pinyin versions of these messages:
对不起，您所拨打的电话已关机。
dui4 bu4 qi3,ning2 suo3 bo1 da3 de dian4 hua4 yi3 guan1 ji1.
对不起，您所拨打的电话已停机。
dui4 bu4 qi3,ning2 suo3 bo1 da3 de dian4 hua4 yi3 ting2 ji1.
hope it helps~hehe~

Thanks guys, that covered pretty much everything. Will be sure to remember the trick with pulling the battery out instead of switching off too, should the need arise