ORIGINAL MAGSAFE 1 60W Power Supply MacBook 2011 2010 A1278 Genuine - TESTED WORKING!Photo is of exact item you'll receive, including the extension cable.
#POWER SUPPLY FOR MACBOOK PRO A1278 INSTALL#
Use QUICK 861DW hot air rework station to remove the IC, apply some solder past to the new IC, and then install the new IC to the motherboard.Item: 303996935006 ORIGINAL MAGSAFE 1 60W Power Supply MacBook 2011 2010 A1278 Genuine. The working condition for IC U9701 is fine, so we can directly remove the U9701. Measure the resistor R9704 2 Pin, it has 3.3V, it's normal. Then measure LCD_BKLT_PWM brightness adjustment PWN signal, generally it's outputted by graphics processor IC, this MacBook Pro doesn't has the graphics processor IC, so it's outputted by MacBook PCH south bridge. PPBUS_SW_LCDBKLT_PWR passes through 2 resistors R9731 and R9715 to split voltage, the voltage measured is 3.1V, which is normal. Next we need to measure the voltage of the C9701 boot Pin EN, for measuring this voltage, we need to connect it to the screen, because only if the motherboard is identified to the screen will it generate a voltage. Measure C9711 1 Pin VDD10, the voltage is 3.3V, it's normal. Use digital multimeter to measure the power supply VIN via capacitor C9710 1 Pin, the voltage is 5V, which is normal. The U9701 IC controls a boost inductor L9701 and boost diode D9701, and recharge or discharge by through boost inductor, and it produces voltage to supply power to the backlight.Ĭheck the working condition of the U9701. Sign in to ZXW online account to check MacBook schematic diagram and bitmap.Ĭheck the relevant circuits of the MacBook screen flex cableįrom the schematic diagram, we know that 21 Pin and 22 Pin PPVOUT_SW_LCDBKLT is backlight power supply, so now we mainly to check the voltage for this signal.
Use screwdrivers to remove the rear case of the MacBook, disconnect the MacBook battery to check if there are obvious damaged marks next to the screen flex cable connector.Īfter checking, the MacBook Pro screen flex cable doesn't have the obvious damaged marks. The MacBook Pro screen flex cable connector on the motherboard is damagedįirst of all, we need to disassemble the MacBook Pro. MacBook Pro screen flex cable is damaged
MacBook Pro motherboard backlight boost problem There are several reasons can cause no backlight on the MacBook Pro: The MacBook model is A1278, the motherboard model is 820-3115-B. The MacBook screen doesn't seem to react after booting, it keeps black, but we can see the Apple LOGO when we use external lights to shine the MacBook Pro screen, which means the MacBook Pro can be displayed, just no backlight. A1278 Macbook Pro no backlight- Solution!