Macbook Pro A1181 Inverter or Light sensor?

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Macbook A1181 Inverter or Light sensor?

Hi All,

I have a Macbook A1181 (non-unibody) with a dim screen. While the LCD was in the laptop it would get bright when the screen was placed on a certain angle.

I have removed the LCD and tested with a separate inverter and it works 100% so I know it's not the bulb. However, now that it's apart I can't reproduce the screen bulb lighting when moving the screen or cables with the original LCD. I'm 90% certain that it's the inverter but I guess it could be the cable leading from the MB to the inverter.

Does anybody have any experience with this model and the screen being dim? If so is it usually the inverter, cable or light sensor?

 

[ClickRight]

Got it, don't waste any time on me! I check the inverter cable with my multimeter and there's 2 broken wires.

Edit: Any recommendation for a supplier for this?

 

[14049752]

A1181 isn't a Macbook "Pro", is it? It's just a Macbook.


I'd guess it's the inverter cable. I've replaced a good number of those...and an inverter shouldn't be affected by the angle of the screen, so I'm not sure why you'd suspect that with 90% certainty...

 

[anonymous Mac Tech]

I'd guess it's the inverter cable. I've replaced a good number of those...and an inverter shouldn't be affected by the angle of the screen, so I'm not sure why you'd suspect that with 90% certainty...

Yeah, on those macbooks when the screen angle affects brightness its almost always that little black 3 wire inverter cable. I've seen this a number of times myself.

EDIT: Just caught the "90% certain it's the inverter."....Wow?

 

[sal13]

Not 100% sure if they have your part, but I just used both of these to but an Imac 2009 hard drive sensor cable. Both had very fast shipping. Should be worth a look. applecomponents.com and gainsaver.com

-Sal

 

[ClickRight]

A1181 isn't a Macbook "Pro", is it? It's just a Macbook.


I'd guess it's the inverter cable. I've replaced a good number of those...and an inverter shouldn't be affected by the angle of the screen, so I'm not sure why you'd suspect that with 90% certainty...

Sorry I'm doing 2 people's jobs today, my technician was away and he works on more macs than I. I had a MBP and MacBook apart and wrote the wrong thing thinking about the MBP. Yes it's plain MacBook

And yes I should have said I'm 90% certain that it's the inverter/cable leading from the MB to the inverter. Not enough coffee this AM and rambling in my sentences incoherently

 

[Zippin]

Got it, don't waste any time on me! I check the inverter cable with my multimeter and there's 2 broken wires.

Edit: Any recommendation for a supplier for this?

When ordering maybe its best to bear in mind that there are two different inverter cables. The early MacBooks A1181 have a different connection to the board than the later ones.

 

[ClickRight]

OK, so the new cable inverter cable came in today, however it is still extremely dim. The brightness control DOES work now (it did not before), but only on two levels it seems. Any ideas?

Edit:

Have checked:

• The new cable - continuity at all pins!
• Disassmbled and checked wiring: All looks good
• Re-isntalled the old inverter (which used to work when the cables were angled) - does not appear to work at all now (not surprising - 2 pins without continuity 90% of the time)

 

[anonymous Mac Tech]

OK, so the new cable inverter cable came in today, however it is still extremely dim. The brightness control DOES work now (it did not before), but only on two levels it seems. Any ideas?

Edit:

Have checked:

• The new cable - continuity at all pins!
• Disassmbled and checked wiring: All looks good
• Re-isntalled the old inverter (which used to work when the cables were angled) - does not appear to work at all now (not surprising - 2 pins without continuity 90% of the time)

Did you try to zap the PRAM? What about when not booted to the OS (maybe just startup holding the option key to enter boot manager to see if its the same there)? How about moving the screen at different angles? Does brightness come and go like it did before?

 

[ClickRight]

Did you try to zap the PRAM? What about when not booted to the OS (maybe just startup holding the option key to enter boot manager to see if its the same there)? How about moving the screen at different angles? Does brightness come and go like it did before?

PRAM reset, no change

Yes it's the same in the boot manager.

No, angles do not matter. I have it pretty torn down and I checked the new cable at many angles, it's perfect.

What I found is the highest 3 brightness settings make a *slight* difference in brightness (it's still extremely dim,) then the 4th down is back to 0.

Edit: PRAM reset, no change

 

[anonymous Mac Tech]

PRAM reset, no change

Yes it's the same in the boot manager.

No, angles do not matter. I have it pretty torn down and I checked the new cable at many angles, it's perfect.

What I found is the highest 3 brightness settings make a *slight* difference in brightness (it's still extremely dim,) then the 4th down is back to 0.

Edit: PRAM reset, no change

I'd imagine a week ccfl tube. I usually see these particular Macbooks in for dim display issues for mostly only 3 reasons.

1. broken display
2. weak/dying ccfl tube in lcd
3. broken/shorting inverter cables

Hardly ever do I see one in that's needed an inverter.

 

[ClickRight]

I'd imagine a week ccfl tube. I usually see these particular Macbooks in for dim display issues for mostly only 3 reasons.

1. broken display
2. weak/dying ccfl tube in lcd
3. broken/shorting inverter cables

Hardly ever do I see one in that's needed an inverter.

Thank you so much for your insight! I hooked the display up to another inverter and it works great! I was thinking it may bay a dying CCFL, however I don't see any pink hue and it works on full brightness on another inverter.

Perhaps the broken/shorted cables caused the inverter to ultimately fail at bad timing?

 

[ClickRight]

Update: On a whim I decided to try a used inverter (it was cheap.) It did not resolve the issue. Reassembled the laptop and gave it back to the client, no charge. Must have been the circuitry on the motherboard that was damaged.

Another client came in the next week with the same laptop, same problem. I said forget it, get a new laptop