u/MadMacTech

Battery shows “service recommended” alert, doesn’t charge & device starts only over the charger, inspite of battery being in a good shape physically.

Motherboard was replaced by Apple under warranty & this time they said battery needs replaced, where battery was good. Client didn’t had enough trust on authorized Center & approached me. Ended up being motherboard issue, corroded RD177 & UD102. These 2 are very important components which are responsible for reporting battery health, charge & condition to the M1 SoC. Since these got corroded, necessary data wasn’t being sent to the SoC, which resulted in battery being reported as damaged or not getting detected by the system, inspite of being connected. Necessary rework done & battery started getting detected by the system, charges normally too.

What can cause a MacBook to die out of the blue & not turn on? This moisture damage at the speaker amp. Since main power rail of the 13.1v is also responsible for turning speaker amp on, it wasn’t turning on. Necessary rework done & MacBook is back to life.

Dead on arrival, Liquid damaged. Corroded TPS62180, which is a 5v regulator for USB-C port on the HDMI port side. This regulator is responsible for supplying 5v to the port, which is for USB & thunderbolt activity. Removed the regulator, replaced it with a brand new one & MacBook is back to life. Apple quoted ₹78,000 for motherboard replacement but it’s repaired for 1/3rd of the price, with all the client data intact.

Stuck at 5v, partial short circuit on the main power rail PPBUS_AON, which is 13.1v. Ended up being shorted audio amp, which we were able to find out using a thermal camera. Shorted audio amp removed, replaced it with a good working one & MacBook is back to life.

Not turning on.

Stuck at 5v, dead short on PP3V8_AON. Ended up being shorted capacitor on the same line, which got cracked & blown. Cracked cap removed, necessary rework done & MacBook is back to life, with all the client data intact.

Been struggling with this since a month & had a relearn everything I know for fixing this device.

Stuck at 5v, severe liquid damage in UG400 (USB-C port controller on the HDMI side). This one controller is programmed & Apple designed this controller in a way that no off the shelf controller will work, in case we have to replace it for any purpose. So had to buy an entire CPU dead motherboard, harvest parts from it & replace the damaged ones with the harvested ones. Also had rework on the connections whose solder pads got burnt due to liquid damage. Finally device works as it should with proper voltage & ampere draw.

Stuck at 20v/200-300mA, where it should be at 1A & above for the battery to charge. Generic moisture damage to the resistors which are responsible for I2C communication between the motherboard & battery, for the battery to get detected. Necessary rework done to clear the corrosion, replaced the necessary resistors for I2C & battery is back to its charging & working condition. Apple Store wanted to replace the motherboard but it’s fixed at 1/3rd of the motherboard replacement cost with all the user data intact.

A2289 13” MacBook Pro 2020 touchbar. Partial short circuit of 89.5 ohms on main power rail of 13.1v (PPBUS_G3H), which should be OL (Open Line). It ended up behind speaker amp. Up & running with all the data intact. ✅