Yesterday, we got an iPhone 6, this iPhone 6 WIFI is grayed out, we need to find the solution for iPhone 6 no WIFI trouble.
There are lots of solder flux cover on WiFi, it seems that WiFi has been replaced several times, a nearby resistor is also lost , the bottom of WIFI is scraped to copper wire.
According the trouble phenomenon, we can certainly confirm it’s not the iPhone 6 WIFI module problem.
First remove the WIFI IC and boot device to measure the voltage of WIFI bottom board pin, we find that 14 pin has no signal voltage, it should be 1.8V. The problem comes from here. Using a digital multimeter to measure but no resistance, so we use WUXINJI bitmap to check and find it is directly through CPU, is it the bottom board wire disconnection?
Check the WUXINJI Schematic Diagram, It can be seen that the iPhone 6 bottom board wire is really disconnected. Now we have to see if there is another way, continue to look at the principle diagram Apple 6.
This reset signal has a capacitor and a pull-up resistor. The capacitance is next to WIFI. There is no resistance in the measurement. This is hopeless, then we look at the pull-up resistor again, find it is on the back of the iPhone 6 CPU from the bitmap, and it’s very close.
Measuring resistance is 446, then directly solder jumper wire by QUICK 861DW, install WIFI, but the icon is still gray. Then we think the WIFI may be broken, so we immediately replace a new WIFI chip.
After finish the above step, we assemble the iPhone and turn on it to check, the Bluetooth is back to normal, the WIFI can be used now. The repairs end!