NOKIA EXPRESSMUSIC 5800 SIM NOT VALID - Nokia 5800 XpressMusic Smartphone

Remove SIM and check on another phone, if this does not work replace card. If not clean the connections and try Also if is possible that the phone has hung up because there are errors in the software. So to reset remove the battery and the memory card from the phone. Using your PC , scan the memory card for any corrupt files or media files with virus- it is possible when they are downloaded from unsafe sites. If so remove or format the card. Now replace the card and battery and switch on the phone. If the phone hangs up then it is confirmed that the software is corrupt and will need a reinstallation. Seeking help from the authorized service /support centre is most ideal. Take estimate and decide.