Good morning everyone,
I have an imac 21 A1418 with logic board 820-00431-A that has power problems.
Specifically, with power on, only one LED (1) lights up and when I go to press the power button it goes off for an instant but nothing happens, then it turns green again.
I also tried another power supply but the result did not change.
I measured the various binaries in diode mode but everything seems to be normal, apart from the PP5V_S4 which is clearly shorted.
I measured the various voltages and they are all present.
I have tried removing C4702 and C4602 and other components around them including R7300 , u7300 , c7300 but the short is still there.
I injected 1v on pin 1 C4702 and had 3 amps but with thermal imager I noticed only slight heat on Q7650 (could it be bad?) belongs to 5V S4 Regulator circuit.
Any suggestions ?
I have an imac 21 A1418 with logic board 820-00431-A that has power problems.
Specifically, with power on, only one LED (1) lights up and when I go to press the power button it goes off for an instant but nothing happens, then it turns green again.
I also tried another power supply but the result did not change.
I measured the various binaries in diode mode but everything seems to be normal, apart from the PP5V_S4 which is clearly shorted.
I measured the various voltages and they are all present.
I have tried removing C4702 and C4602 and other components around them including R7300 , u7300 , c7300 but the short is still there.
I injected 1v on pin 1 C4702 and had 3 amps but with thermal imager I noticed only slight heat on Q7650 (could it be bad?) belongs to 5V S4 Regulator circuit.
Any suggestions ?
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