No service issue in my iphone 8 plus

After updating the latest ios software, my iphone 8 plus is showing "No service". Checked with a local apple authorized service center. After checking the phone, they recommended that it could be an issue related to the board and it is better to replace the iphone. They said there is no warranty/guaranty of the repair done on board. So, it is better to replace the phone.

is this a correct solution? is there any other solution?

Pl. support.

Regards,

V. Manoharan