RESQ-MYTECH
New member
Hi all. Not posted for a while as I seem to be getting on OK with the logic board repairs. However, I think I am not seeing the wood for the tree's. I am searching around and losing track of what, where, why and when.
MBA A1466 820-00165
Magsafe- Green to Orange- no power on- no fan spin
PPBUS_G3H = 8.597v
PP3V42_G3H = 3.428v
PP5V_S5 = 0V
PP5V_S4RS3 = 0V
PP5V_S0 = 0V
PP3V3_S5 = 0.307V
PP3V3_S4 = 0V
Basically, all the 3v3 rails are 0v
I have seen this issue addressed a few times on the forum and by our "leader" but for the life of me I can't seem to locate any of the videos or posts. I am probably not putting in the right search terms but being thick.. who knows.
My deduction, I believe there is an IC that produces both the 5v and the 3.3v.
Searched over the board and so far, there was corrosion around pins 18 to 21 on U7501 so I removed and replaced it with another.
Corrosion around pin 1 of R4411 and all 6 pins on Q4410. Q4410 was replaced. Pad on pin 1 of R4411 was gone so jumped to pin 1 on R4410.
checked rest of the board.... no corrosion. I don't think the board has been looked at before as even though it is cleaner that I would have thought as there was a little corrosion, there are loads of fibres on the board giving me reason to believe it has not been ultrasonic cleaned.
Prior to disassembly, I did do a SMC reset and a PRAM reset. I have also tested SMC_RESET_L which gives 3.384v and SMC_MANUAL_RST_L gives 2.754v
When the magsafe i connected the CPU does get warm. And even though I do not believe for one second it is a contributing factor, I have "carefully" removed J6100. I don't know why but Louis seems to have good results removing this.
Is there anything else I should be checking, please?
Thank you in advance.
MBA A1466 820-00165
Magsafe- Green to Orange- no power on- no fan spin
PPBUS_G3H = 8.597v
PP3V42_G3H = 3.428v
PP5V_S5 = 0V
PP5V_S4RS3 = 0V
PP5V_S0 = 0V
PP3V3_S5 = 0.307V
PP3V3_S4 = 0V
Basically, all the 3v3 rails are 0v
I have seen this issue addressed a few times on the forum and by our "leader" but for the life of me I can't seem to locate any of the videos or posts. I am probably not putting in the right search terms but being thick.. who knows.
My deduction, I believe there is an IC that produces both the 5v and the 3.3v.
Searched over the board and so far, there was corrosion around pins 18 to 21 on U7501 so I removed and replaced it with another.
Corrosion around pin 1 of R4411 and all 6 pins on Q4410. Q4410 was replaced. Pad on pin 1 of R4411 was gone so jumped to pin 1 on R4410.
checked rest of the board.... no corrosion. I don't think the board has been looked at before as even though it is cleaner that I would have thought as there was a little corrosion, there are loads of fibres on the board giving me reason to believe it has not been ultrasonic cleaned.
Prior to disassembly, I did do a SMC reset and a PRAM reset. I have also tested SMC_RESET_L which gives 3.384v and SMC_MANUAL_RST_L gives 2.754v
When the magsafe i connected the CPU does get warm. And even though I do not believe for one second it is a contributing factor, I have "carefully" removed J6100. I don't know why but Louis seems to have good results removing this.
Is there anything else I should be checking, please?
Thank you in advance.