When your Macbook doesn’t turn on, your first guess should be your Mac has run out of battery. If it’s not the case, you need to search more other reasons. We might have browsed a series of posts or threads like MacBook Pro No Power on; MacBook Power Key Not Working; MacBook won’t turn on etc.. This problem usually relates to one of two things. Either the display is malfunctioning, which means the computer is on, and you just can’t see that it is, or there is some kind of power-related issue that is preventing it from turning on as expected. REWA LAB has been working on MacBook repair these days, and in this tutorial we look at the steps you need to take to fix your MacBook Pro 13” A1278 if it won’t turn on when pressing the power button.
Detail steps to teach you How to fix your MacBook Pro or Air won’t turn on :
1. Power Button Power Up Testing
Power button power up-failed. Plug in AC adapter to power up- successful.
2. Keyboard And Trackpad Testing
Keyboard and Trackpad no function.
Preliminary Diagnosis
Trackpad and keyboard module broke down.
3. MacBook Disassembling
Disassemble the MacBook and disconnect flex cables. Remove screws and detach the motherboard. Then remove the memory.
4. Motherboard Superficial Inspection
Motherboard superficial inspection with the help of a handhold magnifier.
5. Maintenance Drawing Referring
Roll out the maintenance bitmap and the circuit diagram for reference. Roll out Motherboard framework drawing and motherboard power system architecture afterwards.
6. Motherboard Voltage Testing
Locate voltage 12.56 V, common point voltage 3.42V, voltage 5V, voltage 3.3V, voltage 1.5V, voltage 1.0V, voltage 0.9V, voltage 1.1V. Connect AC adapter and test them with digital multimeter – all display normal value.
Disconnect AC adapter and install the memory. Then connect AC adapter and test, voltage value jumps from 1.1V to 0.8V- normal circuit.
7. Resistance Testing
Test keyboard port pins and peripheral component value with diode mode. Then connect AC adapter and test keyboard port power supply voltage with digital multimeter. Resistor R5704.1 displays no voltage (3.3V under normal circumstances).
Diagnosis
Analyze with the help of maintenance bitmap and circuit diagram – U5701 broke down.
8. U5701 IC Replacing
Use a metal plate to protect keyboard port from high temperature, then take down the damaged U5701 IC with hot air gun. Apply some BGA paste flux to the bonding pad and align the new IC with hot air gun.
After that, test R5704.1 with digital multimeter again – 3.3V (normal value).
9. Assembling and Testing
Assemble the MacBook. Power button power up-failed. Plug in AC adapter to power up- successful.
Keyboard and Trackpad work normally.
Diagnosis
Keyboard power button no response – keyboard need to be replaced.
10. Keyboard Replacing
Disconnect flex cables and detach the motherboard. Then detach the old keyboard and install a new keyboard.
11. Assembling and Testing
Assemble the MacBook. Power button power up-successful. Keyboard and Trackpad work normally.
12. Final Fault Diagnosis
Keyboard and motherboard IC broke down resulted in the “not turning on” problem.
Tools Used:
- Multimeter
- Screw Driver
- Tweezers
- Hot Air Gun
- Soldering Iron
- BGA Paste Flux
- Anti – static Glass Wiper
- Solder Wire
