Game Boy Micro: broken flex cable resulting in no back light

[Ozito]

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.

[Niku-Sama]

Looking at it, the connector for the screen on the main board looks like it might be missing a part on the right side. It might be just your it is in the micro but I recently repaired a phat ds and it has similar connectors in places and both ends of them were smooth on top where yours looks like it might be missing something to keep tension down on the edge connector to make a good connection. If you know what I mean...

It would explain why it goes on and off.
Plug the screen back in and press in that right side of the connector and if it comes on then it's not the screen or ribbon, it's the connector.

I'm at work now but when I get home I'll circle and repost what I'm talking about if your not catching what I am saying.

[Ozito]

Thanks for the input niku.

I guess you´re referring to the "P3" connector (the small one on the left) for the back light.
I'm 99.9% that's not the problem but i gave it try just to be that 0.01% extra sure and it doesn't fix it.

I don't know if i was clear on the first post about the board to the left
That board seems to have some vital connection for the back light since flexing it backwards makes connection to the main board thus lighting the screen up.

I have also noticed that the connection for the d-pad button are becoming corrupted too (has to be the flexing) so i guess I'll have to track them too, to the other side (main board).

Thank you again