820-00165 Macbook Air 13" Green & Orange Light No Fan Spin

[KappaDev]

I have an 820-00165 board with no visible corrosion or liquid damage.
Laptop is a 13" Macbook Air (2017). When MagSafe is plugged in, light goes green and then stays orange without any fan spin after that.

I took some readings and it looks like PP5V_S4RS3 is missing. It has an odd 20 ohms to ground so seems like its not a complete short.

PPBUS_G3H - 8.59V
PP3V42_G3H - 3.439V
PPVRTC_G3H - 3.333V
PP5V_S5 - 5.005V
PP5V_S4RS3 - 0V (20ohm to gnd)
PP5V_S0 - 0.443V
PM_SLP_S4_L - 0V

Charger is genuine, no noticeable areas getting hot.

[piernov]

Re: 820-00165 Macbook Air 13" Green & Orange Light No Fan Spin

20 ohms to ground on PP5V_S4RS3 is a problem, should be several kohms at the very least.

With 20 ohms you may be able to find something warming up by injecting 5V but it'll not be easy. Thermal camera would help a lot in this instance. When injecting, start at 1V and make sure voltage isn't leaking to PP1V05_S0, then you can increase up to 5.5V max.

Otherwise you can remove components one by one until you find the culprit. Start by removing L7520 to see which side the short is on. Remove R6414 too to isolate from the speaker amp (and the filter caps) that are good suspects.

[KappaDev]

Re: 820-00165 Macbook Air 13" Green & Orange Light No Fan Spin

above ^

Doesn't seem to be leaking into PP1V05_S0.

Sadly don't have a thermal cam, removed L7520 and it looks like short exists on pin 1 side (PP5V_S4RS3 side). Removing R6414, 40ohms on pin 1 side (PP5V_S4RS3).

Can't feel anything getting warm (although drawing 180mA when injecting into shorted side of L7520). Anything else I can try or simply leave for a while and keep checking for warm spots?

EDIT: Left injecting current for a minute or two and U7501 area seems warm.

[piernov]

Re: 820-00165 Macbook Air 13" Green & Orange Light No Fan Spin

There are not too many components on PP5V_S4RS3 so if you can't find anything getting warm, the other solution is to remove them one by one. Use the boardview, for the components with only 2 pads (capacitors…) you can just shift them off of one pad. For U7501, U7600 and U8080 you have to remove them completely from the board (and at the end you'll have to put them back obviously) which is a bit more work so do them last.
Still, do a close visual inspection of these components to make sure they're not damaged.

[zpi]

Re: 820-00165 Macbook Air 13" Green & Orange Light No Fan Spin

How many Volts are you injecting?

[KappaDev]

Re: 820-00165 Macbook Air 13" Green & Orange Light No Fan Spin

How many Volts are you injecting?

Started with 1V and after confirming no leak to the PP1V05_S0 moved up to 5V.

Also realized that the short is only present when MagSafe is plugged in, if that helps any.

[KappaDev]

Re: 820-00165 Macbook Air 13" Green & Orange Light No Fan Spin

Short is gone after removing U7501. Guess I'll have to find a donor lying around and swap it out.