Macbook air A1370 - 820-3024-B - Chime loop

[Gold7even]

Hello to all, this time i meet a symptom that drive me mad !

I have a macbook air 11" A1370 - Board id 820-3024-B (Core i5 1.6 11 (Mid-2011) that is stuck in a boot system loop (chime loop) this computer start and i hear the chime sound that repeat endlessly with only a white screen.

Sometime (rarely) it chime normally (one time) and i can see the blinking folder (this computer doesn't have a ssd for now) after a certain delay.

I realized that if i unplug the lvds cable i does not have any more chime loop… i test on an external screen with adapter but only white screen with sometime (rarely) the blinking folder !

The keyboard seems to not working, (the caps lock doesn't lit) and all keyboard command doesn't respond (Commande ⌘ + Option + P + R etc…) Only the power button do the job !

At first i was thinking the problem is due to an EFI corruption, So i reprogram the efi chip many time (with different bios file) and the symptom is always the same, no evolution...

Because of the keyboard problem, it was impossible to reset the nvram.

Now i was thinking there was a possible shortcut somewhere, do you have any tips related to this motherboard where to put under my investigation ?

The motherboard is corrosion free, the water damage indicator is intact and the board seems untouched but i don't know the past of this laptop…

Have you ever experienced the same symptoms and successfully repaired the motherboard ?

Thanks in advance for your feedback,

Thomas from France

[dellxps15]

Re: Macbook air A1370 - 820-3024-B - Chime loop

any usb keyboard should work fine... just unplug yours, then power on shorting pins and then try reset nvram by pressing right combination, if i remember good, option is alt, cmd is control and the other key is windows key.

check if it do that reset option 2 times for completing nvram then release bottons.

[Gold7even]

Re: Macbook air A1370 - 820-3024-B - Chime loop

Thanks for your response, i have already try to disconnect the internal keyboard and use an external apple usb keyboard but with no luck (caps-lock doesn’t lit) and still no response to cmd ⌘ + Option + P + R or Option (⌥) to select the boot device !

[Gold7even]

Re: Macbook air A1370 - 820-3024-B - Chime loop

Also if anyone has a "ME Region clean" efi bin dump for my motherboard i am interested.

[amrahmed47]

Re: Macbook air A1370 - 820-3024-B - Chime loop

i ned faile bios .bin

[zeypibytescss]

Re: Macbook air A1370 - 820-3024-B - Chime loop

please upload....

[Gimi]

Re: Macbook air A1370 - 820-3024-B - Chime loop

Hi. Have you tried loading os from an external drive?