Got another conundrum on my hands.  I have someone who wants me to put a bivert chip into their backlit DMG.  Since they got the backlight a while ago and someone else installed it for them, they're not 100% on the details, but they're fairly certain it's a V2 backlight from Handheld Legend.  Here's what's going on:
Running off batteries, the contrast wheel has to be cranked all the way for the image to be even visible.  On AC, it's even less visible.  After installing the bivert, it's basically blank.  The solder points used were the two below the LCD on the front PCB.  No resistor was installed--could this be it?

Any thoughts?
They only hired me to put in that bivert chip, but I'd rather not give them back a gameboy that you can't see anything on.

Thanks!