I have a 2017 MacBook Air with a very odd charging issue. Sometimes, it won't charge and there is no lit LED on the MagSafe and it cannot boot (dead battery), BUT if I leave it connected like this for about a month, suddenly the green LED lights and it will boot from a fully charged battery. I can use it in this condition with Magsafe connected and LED green for as long as I want. BUT if I disconnect the MagSafe and then reconnect it, the LED is now off and the battery runs down gradually until it won't boot again. If I leave it another month with the MagSafe connected, the LED-suddenly-lights-again cycle repeats over. Interestingly, if I connect a non-Apple USB to Magsafe charger (Anker) to it while it is in this state, the green LED immediately lights for about a minute and it boots and shows as charging, then turns Amber for 30 s and then goes off and stops charging. I've tried all the normal tricks with SMC and NVRAM. From reading a few sites, it seems this is a typical problem with the reverse current protection transistor in the charging circuit.
I'm going desolder and replace it (I have the necessary skill and solder station) but the first thing is to find the rating/model of this transistor (it's illegible if I am looking at the right part). Does anyone have circuit diagrams for this MBA 2017 or the details of this transistor?
I'm going desolder and replace it (I have the necessary skill and solder station) but the first thing is to find the rating/model of this transistor (it's illegible if I am looking at the right part). Does anyone have circuit diagrams for this MBA 2017 or the details of this transistor?
Last edited: