Fix iPhone 6S black screen issue by logic board repairing

The iPhone 6S is turned on, but the iPhone 6S screen is black. In order to fix iPhone black screen problem. After replace the iPhone screen, the black screen problem still there. So, we need to check iPhone logic board and repair it.

Disassemble the iPhone by phone opening tools, and carefully remove the iPhone logic board.

Connect iPhone to the DC power supply to measure its boot current, the current tested is normal, no large current failure, now we need to check if it has a display but no backlights. Check it under the light, we find the iPhone has a display.

Measure the display socket by Fluke 15B+ Digital Multimeter, we find some pins are corroded, but the resistance value data tested is normal. We need to take off the CPU shield, we found that one end of this capacitor was seriously corroded.

Check iPhone schematic diagram in the WUXINJI Dongle, this component is responsible for backlight power supply. Carefully remove it by QUICK 861DW hot air rework station, and then install the new one.

Now, install the iPhone logic baord and connect the iPhone battery and iPhone LCD screen , now the screen displays properly, the iPhone black screen has been solved!