MacBook A1278 2009

[alfredomfr1]

This mac turn on ok, but the screen was completely white.
fuse 1 defective (see image), after replace the fuse 1, screen without backlight but can see image in the dark
the fuse 2 defective now.
Any help?

[keeney123]

Re: MacBook A1278 2009

There should be a backlight enable FET that you should be able to check.

[dellxps15]

Re: MacBook A1278 2009

1 is not a fuse if i remember good....

2 is backlight fuse.

if fuse 2 is blown... check if one side has 12.5 volt. if yes...... remove all sort of power and check if side 2 has short. if no short replace 2A fast blow 24-32volt 0402 fuse and backlight should be back ok.

backlight ic is the one near lvds connector and up that component u called " fuse 1"

[alfredomfr1]

Re: MacBook A1278 2009

Thank dellxps15 and keeney123, I will try today

[mpp]

Re: MacBook A1278 2009

According to schematic, 1 is a Cap. 200Pf 5% 100V CERM 1206.
(it is on the backlight circuit).

[alfredomfr1]

Re: MacBook A1278 2009

I leave 1 open and replace fuse 2, it is working now.

[keeney123]

Re: MacBook A1278 2009

Good for you. I have not a looked at the schematic. Perhaps Cap 1 is for transient spikes or it allow the circuit to discharges?