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Hello
I have a Macbook a1286 820-2915-B and my screen backlight no longer work.
I change the LVDS cable but it did not change anything...
what is borken ? the graphic card ? the screen ? or the F9700 fuse or the Lp8545SQX chip ? or other ?
thank you for your help
( sorry for my english i'm not an english ^^ )
Ist dies eine gute Frage?
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Connect to an external monitor. If you see a normal image your GPU/logic board is ok and the damage is most likely the chip or fuse.
You'll have to examine the logic board under a magnifying glass to look for visible damage to each part to determine what has been damaged. Cleaning the board may be a solution also so you may want to start your repair effort with that.
If this answer is acceptable please remember to return and mark it accepted.
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Look for discoloration (corrosion) or burn (brown) marks. Look for swollen or damaged components. Since the external works then your GPU and logic board are ok it is likely the fuse or controller for the LED circuit.
There are no trace of corrosion or combustion and i do not see any damaged component. How can i check the fuse or the controller for the LED circuit ?
Thank you and have a good day
Goowie, is this the same machine, or a different one? If it's the same please don't open multiple Questions for the same machine and problem.
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Goowie, why would you think it is your LVDS cable? It is possible, but your picture is not clear enough to see any damage. You can change the cable and if it still does not work, check the backlight fuse, FET's, backlight driver and other components. Of course you did clean your board with high grade isopropyl alcohol and checked for any kind of corrosion.
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I think the two or three first pins of the connector are damaged. I'd also check the socket for a short in this section.
thank for you reply
but I looked at the schematic and the two pins that are on Damages in my photo are those of the backlight. After I have a multimeter but I do not know how to test the F9700 and LP8550 IC chip
someone can help me ?
thanl
lemerise is absolutely right. The pins are definitely damaged. Use a multimeter,( I prefer an inexpensive analog) and (depending on the meter) set it to the ohm scale. By touching both probes together your meter needle should move. Touch either end of the fuse with a probe and you should see the needle more. If they move, you have continuity. Since your cable looks like it got shorted out, you also want to check the LVDS connector.
I tried with a multimeter and fuse F9700 gives O Ohms. Is this normal?
But tonight (french time), I'll disassemble my screen to test the LVDS cable
Update : actually the multimeter reads "Open Loop" when I put the two probes to extremities of the fuse F9700
Si le circuit de la "fuse" est ouvert c'est qu'elle est "sautée" et doit être remplacée. Il faut aussi minutieusement vérifier l'intérieur du "LVDS socket" avec une loupe pour constater son état. En utilisant le multimètre en mode continuité vous pouvez aussi vérifier la continuité entre les 3 premières pins du LVDS socket et les éléments constituant les circuits sur la carte-mère.
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If the fuse is open circuit then it must be replaced. You should also check the inside of the LVDS socket for any sign of short (black spot, etc). With the multimeter you can also verify continuity from the affected pins to their associated components on the logic board.
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Hello !
With a mini-display adapter to hdmi, external screen work very good.
I examine the Logic Board but i don't see something broken...
Who can i Check backlight chip or fuse ?
Thank you and have a good day
von Goowie