Review on SunFounder I2C LCD Module Shield for Arduino R3 Mega2560 - 2004 20x4 Serial TWI by John Huskisson

Arrived, installed the Liquidcrystal_I2C library, ran the sample code. Heroes are not visible, but they are. There's just no backlight. I've played with it but to no avail. But wait. Then I noticed two jumpers on the back of the unit, but no documentation. Just in case, I connected the two pins together and voila! backlight. I'm not sure why there is no documentation for these pins, but I wanted to change my rating from 1 star (no backlight) to 5 stars (works great). Bottom line: when you get the LCD, look for two pins on one end of the adapter. If it's jumpers, then ok. If not, connect them together. This can save you time, frustration and frustration. Note on SunFounder: Activate your documentation!