Macbook Air A1932 Does not Turn ON
Hello fellas!,
I have this macbook air with water damage, board 820-01521
After cleaning the board and checking for possible damage I can't find anything unusual, I'm a bit of a newbie and maybe my question is obvious to many although I haven't found much more info.
After measuring all the power rails I find the following losses PPVCC_S0_CPU and PPVCCGT_S0_CPU, the chip that controls them is the U7100 and if it is providing the rail of PPVCCSA_S0_CPU.
The signals CPUVR__PGOOD, CPU_VR_EN are OK.
Although CPU_VIDALERT_L is low and I see no activity in the SDA and SCLK of this chip.
On the other hand measuring the rest of signals that comes to my head I find PLT_RST_L signal low all the time, measuring this line gives me 0.700 a little higher than the 0.500 that I have found as reference.
I also see some activity in the Soc Rom U4770.
I could understand that by keeping the PLT_RST_L signal all the time, at the end the U7100 receives the alert so it doesn't launch the Vcore and VGT rails
Any extra idea what I can test ?.
Thanks for any help guys!!
I have this macbook air with water damage, board 820-01521
After cleaning the board and checking for possible damage I can't find anything unusual, I'm a bit of a newbie and maybe my question is obvious to many although I haven't found much more info.
After measuring all the power rails I find the following losses PPVCC_S0_CPU and PPVCCGT_S0_CPU, the chip that controls them is the U7100 and if it is providing the rail of PPVCCSA_S0_CPU.
The signals CPUVR__PGOOD, CPU_VR_EN are OK.
Although CPU_VIDALERT_L is low and I see no activity in the SDA and SCLK of this chip.
On the other hand measuring the rest of signals that comes to my head I find PLT_RST_L signal low all the time, measuring this line gives me 0.700 a little higher than the 0.500 that I have found as reference.
I also see some activity in the Soc Rom U4770.
I could understand that by keeping the PLT_RST_L signal all the time, at the end the U7100 receives the alert so it doesn't launch the Vcore and VGT rails
Any extra idea what I can test ?.
Thanks for any help guys!!
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