820-01958 5V 0.3A

yair37

Member
dont know history(but no water damage), someone play with the board before.
when it arrive to me PP3V3_G3H_RTC was short, i was fix it.
now, on one usb port it show 5v 0.3a and nothing on the other, i was replace U3200 and fix some caps there and now both usb show 5v 0.3a and every 10sec its of and on again.
PPBUS_G3H 12.3V
PP3V3_3GH 3.3V
 

yair37

Member
with battery connected:
usb port #1 is show 5v 0.3a then off and not turning on again on again(the USB Voltmeter )
usb port #2 5v 0a
 

yair37

Member
all LDO look fine in diode mode and voltage.
D3387 was off i was replace it.
also D3320 was bad and i was replace it.
still act the same..
 

yair37

Member
both 5v 0.25-0.3A whiteout battery.
with battery: its start 5V 0.3A and then sown to 0A and when i take the charger out and plug again its dead, until I'm unplug the battery
 

yair37

Member
i was put 1v with high AMP and after a 1sec the short was disappear and i was get 3.3v on 3V3_G3H_RTC,
i didnt see and bad cap on 3V3_G3H_RTC rail and C7690 was missing so i thought maybe he was blow out.
weird but all 3V3_G3H_RTC rail look o.k.
 

2informaticos

Administrator
Staff member
The "hidden" culprit on 3V3_G3H_RTC is probably the real problem.
This repair is probably waste of time, after board was messed off in other place.
 

2informaticos

Administrator
Staff member
C7690 is not so critical as Apple wants you to believe.

You have now correct 3V3_G3H_RTC, but there is a bad component; which doesn't make its job.
 

2informaticos

Administrator
Staff member
You may find that is correct value, comparing with working board.

Looks like wasting time, once you can't find what was bad component connected to 3V3_G3H_RTC.
Short has gone, but think that internal connection is broken now; it is not powered in fact.
 
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