Hi
Images can be found here
I have a GBM that has the flex cable that connects the smaller board to the MB broken somehow.
It's not severed as you can see in the pictures and it's not torn either.
Now the reason i believe it's the flex cable is because when i move the board so that cable flexes, the back light come's on.
I have tried the lcd on another GBM, and it lights up without a problem, so the lcd as a problem is ruled out.
The voltage across the the back light on the defective MB is 3.88v, it's to low since the voltages on the working one has 8.88v on the lowest brightness setting.
The voltages on the working unit is as following (5 being the brightest setting).
5. 9.66v
4. 9.5v
3. 9.38v
2. 9.17v
1. 8.88v
This was meassured on the P3 connector, on the pins furthest from each other, I even measured on the points LA and LC assuming that they stand for LED Anode and LED Cathode.
So I need some more experienced eyes on this, my soldering is good if that's required to try out any ideas given and if you want me to test any point just post it and I'll do it.
Finally, I took a lot of pictures for anyone that dosen't have a GBM but want to see the circuitry.
Thank you for reading.