smiba
New member
830-3437 - Orange Light, VCore present, Fan spin, SPI Working --> no Chime & Video
I really hope this isn't one of those embarrassing issues where I just overlooked something haha
Anyways, this macbook Air was water damaged and already bought to another company who told "they would need to replace the motherboard as it can't be repaired", I did not notice a lot of corrosion but I did notice some rusty parts and blackness/discolouration on the two backlight power pins of the display connector. (And a blown F7700, it no longer blows after replacement though).
When you plug in the charger it becomes green for about one second, before it turns Orange. (No battery inserted). The CPU fan will switch on/off for about 3-4 times for about 4 seconds until it keeps on spinning. There is no Chime
System responds to pressing the power button and shuts down by keeping it pressed or starts by pressing it just once.
CPU Vcore is 1.75V, the CPU gets warm after keeping it on for a while.
All major power lines are available and at their voltages, SPI chip has both Input and Output communication (Seen with oscilloscope)
When plugging in the battery PPBUS_G3H drops from 8.8V to 6.8V, I don't think this is intended. System does not run off battery, although the battery might just be empty. Possible issue in the power circuit?
No backlight (BKLT_PLT_RST_L signal is Low. The pins on Q7706 look awful but the chip responds as expected. Pin 3&4 (Gate & Source) are about the same voltage), No Keyboard backlight etc.
A lot of the components positive power pin(s) look slightly bad, but this is probably because corrosion usually starts on the positive terminal. Power still goes through them properly and the solder connections are not broken.
Summery:
CPU Vcore = 1.75V
SPI Chip I/O activity
Doesn't run off battery, when having a battery plugged in PPBUS_G3H drops from 8.8V to ~6.8V
No backlight, the FET isn't opened (No power out on PPVIN_S0SW_LCDBKLT_FET)
Fan spins
Orange Light on charger, battery or not
No Chime
F7700 Backlight fuse was blown, replaced and its no longer blowing.
If anyone can help me, thanks a lot!
I really hope this isn't one of those embarrassing issues where I just overlooked something haha
Anyways, this macbook Air was water damaged and already bought to another company who told "they would need to replace the motherboard as it can't be repaired", I did not notice a lot of corrosion but I did notice some rusty parts and blackness/discolouration on the two backlight power pins of the display connector. (And a blown F7700, it no longer blows after replacement though).
When you plug in the charger it becomes green for about one second, before it turns Orange. (No battery inserted). The CPU fan will switch on/off for about 3-4 times for about 4 seconds until it keeps on spinning. There is no Chime
System responds to pressing the power button and shuts down by keeping it pressed or starts by pressing it just once.
CPU Vcore is 1.75V, the CPU gets warm after keeping it on for a while.
All major power lines are available and at their voltages, SPI chip has both Input and Output communication (Seen with oscilloscope)
When plugging in the battery PPBUS_G3H drops from 8.8V to 6.8V, I don't think this is intended. System does not run off battery, although the battery might just be empty. Possible issue in the power circuit?
No backlight (BKLT_PLT_RST_L signal is Low. The pins on Q7706 look awful but the chip responds as expected. Pin 3&4 (Gate & Source) are about the same voltage), No Keyboard backlight etc.
A lot of the components positive power pin(s) look slightly bad, but this is probably because corrosion usually starts on the positive terminal. Power still goes through them properly and the solder connections are not broken.
Summery:
CPU Vcore = 1.75V
SPI Chip I/O activity
Doesn't run off battery, when having a battery plugged in PPBUS_G3H drops from 8.8V to ~6.8V
No backlight, the FET isn't opened (No power out on PPVIN_S0SW_LCDBKLT_FET)
Fan spins
Orange Light on charger, battery or not
No Chime
F7700 Backlight fuse was blown, replaced and its no longer blowing.
If anyone can help me, thanks a lot!