Maybe impossible screen question?

[SuzukiChopper]

Hey everyone. A friend brought his Macbook pro (santa rosa model) to me to have the LCD replaced. He had to use a paper clamp in the corner for it to work properly so I knew the display was toast. The backlight was working fine on it though. Got the new display, hooked it up and tested before re-assembling everything well, just a nice dark display, no backlight. Ok, no problem I'll have an inverter overnighted and replace it. It got here today, put it in and still no backlight! External monitor works perfectly fine.

So here I am stuck looking that the board the cable for the LED backlight driver plugs in to. It's not the logic board and from what I've read is the IO board. I can order a new one and spend another $100 throwing parts at this thing but I'd rather test the output first. My question is would anyone know the pin out for that 5 pin connector and what voltages should on each pin? I've put a meter on it and have this:

Pin 1 (brown wire) - 0v (0 ohms to ground)
pin 2 (green wire)- 12v
pin 3 (red wire) - 5v
pin 4 (blue wire) - 0.05v (2.2 ohms to ground)
pin 5 (no connection) - 0v

I think my issue is with pin 4 (blue wire) but I'm not positive. If it's anything like an inverter for a CCFL then one pin (guessing pin 4) should be the control voltage for output (brighter or dimmer screen). No matter what I do, this pin stays right around 0.05v.

I guess to go along with this, if 0.05v isn't correct, what's the max voltage for that pin? Maybe I can hack around it to put the display at 80 - 90% brightness. (Yes I checked the software control when I had the external monitor hooked up, it's cranked and not 0).

 

[bargsbeer]

Hey everyone. A friend brought his Macbook pro (santa rosa model) to me to have the LCD replaced. He had to use a paper clamp in the corner for it to work properly so I knew the display was toast. The backlight was working fine on it though. Got the new display, hooked it up and tested before re-assembling everything well, just a nice dark display, no backlight. Ok, no problem I'll have an inverter overnighted and replace it. It got here today, put it in and still no backlight! External monitor works perfectly fine.

So here I am stuck looking that the board the cable for the LED backlight driver plugs in to. It's not the logic board and from what I've read is the IO board. I can order a new one and spend another $100 throwing parts at this thing but I'd rather test the output first. My question is would anyone know the pin out for that 5 pin connector and what voltages should on each pin? I've put a meter on it and have this:

Pin 1 (brown wire) - 0v (0 ohms to ground)
pin 2 (green wire)- 12v
pin 3 (red wire) - 5v
pin 4 (blue wire) - 0.05v (2.2 ohms to ground)
pin 5 (no connection) - 0v

I think my issue is with pin 4 (blue wire) but I'm not positive. If it's anything like an inverter for a CCFL then one pin (guessing pin 4) should be the control voltage for output (brighter or dimmer screen). No matter what I do, this pin stays right around 0.05v.

I guess to go along with this, if 0.05v isn't correct, what's the max voltage for that pin? Maybe I can hack around it to put the display at 80 - 90% brightness. (Yes I checked the software control when I had the external monitor hooked up, it's cranked and not 0).

Sorry I don't have an answer for you, But this seems very interesting, please keep us updated to your results. The only thing I can recommend that I do, Is purchase an entire display unit instead of just the LCD that way it's pretty much plug and play.

 

[SuzukiChopper]

Sorry I don't have an answer for you, But this seems very interesting, please keep us updated to your results. The only thing I can recommend that I do, Is purchase an entire display unit instead of just the LCD that way it's pretty much plug and play.

I would have done that but the cheapest new display and clamshell I found was ~$600. For this, the LCD was $187 and inverter $40. Even $70 for the IO board keeps the total repair just under $300.

I'm sure someone has this information and is willing to share it but if not then I'm breaking out my development board and am going to test that blue wire and go for broke. At least the inverter will protect the LCD worst case.