Hi gooday i have a very technical issue here with a Macbook pro 2012 820-3115-B which is gives me a greenlight but no fan spin and doesn't seem to power on.On my bench power supply i get a reading off 19v 0.15 A and it stays there..I have checked for all major voltage requirements and most of them are present..I even have another identical working board that i use to compare voltages.But i still can't figure out the issue..Can u guys please help me maybe trace it down? I have all tools to remove and also measure ics and capacitors..Thanks
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Re: Macbook Pro 2012 Greenlight but not Power On
Go down the list of power rails on the schematics and list all voltages.
Also history of the machine always give hints.OpenBoardView — https://github.com/OpenBoardView/OpenBoardView -
Re: Macbook Pro 2012 Greenlight but not Power On
Ok sir i have attached all the voltages listed below...Funny enough while going tru the first set of voltage testing i noticed the Power Supply only drawing 0.01 Amps which is strange..Because before i was getting 0.14A and some of the voltages which are now 0v was giving me readings..Weird..But the history of this machine is that it came in from a friend for both usb ports not working..Everything else was functioning properly and working..I removed and replaced U4600 from a donor board ..I powered it up and while it was booting the whole system just shut off...And that was when i started having this no power issue..So as of now it gives me intermittent greenlight..It stays on green for 5 seconds then goes..And comes back after 60 seconds then goes..now it's drawing 0.01A
PPBUS_G3H =12v
PPBUS_S5_HS_COMPUTING =12v
PPBUS_S5_HS_OTHER_ISNS = 12v
PPDCIN_G3H = 19v
PP3V42_G3H = 3.42v
PPVRTC_G3H = 3.45v
PP5V_S5_P18V5S5_VIN = 5v
PP5V_SUS = 0V
PP5V_S0 = 0v
PP3V3_S5 = 0v
PP3V3_SUS = 0v
PP3V3_S4 = 0v
PP3V3_S3 = 0v
PP3V3_S0 = 0v
PP1V8_S0 = 0v
PP1V5_S3 = 0v
PP1V5_S3RS0 =0v
PP1V5_S0 = 0v
PP1V05_SUS =0v
PP1V05_S0 = 0v
PPVCORE_S0_CPU = 0v
PPVCORE_S0_AXG = 0v
PP1V5_S3_CPU_VCCDQ = 0v
PP1V05_S0_CPU_VCCPQE = 0v
PP1V8_S0_CPU_VCCPLL_R =0v
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I am looking at an A2337 and found this for the order of power rails and what they do. Can this be confirmed before I dive into hunting down power rails that do not exist or are not neccisary?
- PPBUS_G3H (12.6V-12.8V)
- This is the main power rail that supplies power to the entire system. Check this rail first, as it must be present for other power rails to work.
- PP3V42_G3H (3.42V)
- This power rail is derived from PPBUS_G3H and is used to power the SMC (System Management Controller) and other essential circuits. It should be present if PPBUS_G3H is working correctly.
- PPVRTC_G3H (3.3V)
- This
- PPBUS_G3H (12.6V-12.8V)
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Gooday people i have a 820-3115-B Macbook pro 2012 that gives me greenlight but does not power on...History of the machine was there was no green-light and dead.And i replaced the ISL chip for brand new 1...Greenlight now but will not power on automatically or fan spin.I checked most of my relevant power rails and i realize that PP5v_S3 is missing...It's drawing 0.02 Amps Possible you guys can help me pinpoint the issue? btw 12.58v on PPBUS_G3H
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