which software to flash sony ericsson c510

Sorry about this question but i could not find any informations about it.
since a week ago i have problems with my c510, it not recognize any Sim card. I will try to flash it may resolve this issue. With Seus no chance it says that my phone is up to date and there are no Updates available. In Se tool lite 2 my phone doesn't appear in the device list. in XS++ i get no information about my phone. Everything is N/A

Is there any free way to flash my c510?

Use A2 uploader or Omnius,Omnius is free for A2 platform.If problem not solve then it is hardware problem so you'll have to take it to some repair shop.