If you are not sure about the device address of your I2CLCD, please run the following (attached) address scanner program. You can edit this program to specify the range addresses to check. The preset setting is: 0x20 - 0x3F.
And then, you may try using #include <LiquidCrystal_I2C.h> Library. Mine I2CLCD works with bot this library and HD44780 library.
Address_Search.ino (520 Bytes)