Tiny RTC module doesn't work properly when connected to an Arduino Uno together with 16x2 LCD
An I2C scanner sketch can help to identify the actual addresses in use. I would use a sketch like on this page https://playground.arduino.cc/Main/I2cScanner or on this page http://gammon.com.au/forum/?id=10896&amp;reply=6#reply6 . Or google 'arduino i2c scanner'.

Hook up the RTC by itself and run the scanner, then hook up the LCD by itself and run the scanner. The output will be on the serial monitor. If the devices have the same address, then that is your problem.

If one of the devices does not show up at all, then perhaps it is defective.