Sony Ericsson s710a Troubleshooting
Battery is constantly low
Battery does not hold a full charge.
If you have had your battery for over 2 years and the usage time continues to drop, you should consider replacing the battery. See the Battery Installation Guide.
A suggestion for sustaining battery life is to avoid overcharging the battery. Only charge the battery when necessary (about 10% charge left).
If the battery replacement does not return the battery to a normal level, the motherboard should be checked for any issue if possible. See Motherboard Installation Guide
Settings are not default
The settings on the phone have been adjusted and you want to restore the phone to its original state.
Settings have been changed and need to be reset
The device can be reset manually. When resetting the phone, you will have the option to Reset Settings or Reset All. The first option will change the settings back to default and the second option will delete all data (including downloaded content) and reset the settings.
In order to reset the phone, go to Settings->General->Master Reset. You can choose Reset Settings or Reset All. You will then have to enter the phone lock code, which is by default 0000.
Phone does not turn on
The phone does not power up.
Either the battery needs to be recharged or replaced. See the Battery Replacement Guide to learn how to do this.
Phone does not indicate charging
The phone is plugged in and does not show this on the screen.
The charging connector is loose
Check to make sure that the proper charger is being used and that the connection with the phone and electrical outlet is snug.
The phone has a drained battery
If the device has a drained battery or the battery has not been used for a long period, the charge symbol may take up to 30 minutes to appear on the phone.
Phone language is incorrect
The phone menu is in a cryptic foreign code.
Phone has been set to a foreign language
If the phone is set to a language you don't understand, you can set it to the default (determined by the SIM card) by pressing the right directional button, then entering 8888, then pressing the left directional button while the phone is in standby. To always choose English, do the same key combination, but enter 0000 instead.
Phone is locked
Your phone is locked and you're unable to access the menu.
Phone was locked unknowingly
The phone comes with a default lock code of 0000. This can be changed to any 4-8 digit code if desired.
You are unable to connect to your network provider.
Out of range of signal
If the phone is showing no cellular network available, it means that you are not close enough to a signal from your network provider. Try locating a cellular tower or, if inside, move outdoors to improve reception ability.
No network provider in country
You may be in a country or region where there is no cellular provider that can be accessed by your phone. You may be able to buy a new SIM card to solve this problem. See the SIM Card Installation page for more help with this.
You receive an error message that prevents the phone from being used.
Get Message: "PUK Blocked"
If you get this message, it means that your Personal Unblocking Key code (PUK) was incorrectly entered ten times in a row. You must contact your service provider to rectify the issue.
Get Message: "Charging, Alien Battery"
If you get this message while the phone is charging, it means that the battery in the phone is not a Sony Ericsson approved battery.
Get Message: "Insert SIM"
This message means that there is no SIM card in the phone. You must install a proper SIM card in order to use the device. See the SIM Card Installation Guide for step-by-step instructions.
You may also get a message that says Insert correct SIM card, which means that you are not using a SIM card that is compatible with the phone.
Menu options grayed out
You are trying to access a menu option, but it is gray and not black.
The menu option is not accessible
If an option is grayed out in a menu, it means that the function is not currently available.
Source: Sony Ericsson s710a User Guide