What is this IC marked IA89G or 1A89G?
Much as it might look like the CAT37 label on the PCB means "CAT component 37", it appears that it's actually an LED driver boost converter:

http://www.onsemi.com/PowerSolutions/product.do?id=CAT37

And FWIW, this converter looks like it's intended to power 4 white LEDs, so perhaps your tester equipment has a display with white backlight, or is able to test the backlights of LCDs under test?