Loosing GSM, data transfer and WiFi signal/ranges. Water damaged.

Cell was water damaged. Display was not lighted. Display started functioning properly after it get dry. However, cell phone generated a lot of heat and become hot. After 2-3 hours of listening musing, cell stopped generating heat, and become cool. However, there is problem with cell range (GSM, data transfer and WiFi). Cell needs to have strong signal to get connected with the net (GSM, data transfer, WiFi. Bluetooth was not checked). Cell phone works properly, the only fault is very weak signal. Which component is affected?

I’m electronics beginner, therefore please respond in easy manner.