{"id":2176,"date":"2018-05-30T00:00:00","date_gmt":"2018-05-30T00:00:00","guid":{"rendered":"http:\/\/192.168.2.19:8666\/?p=1"},"modified":"2024-09-18T18:20:31","modified_gmt":"2024-09-18T10:20:31","slug":"troubleshooting-iphone-8-plus-black-screen","status":"publish","type":"post","link":"https:\/\/rewa.tech\/fr\/troubleshooting-iphone-8-plus-black-screen\/","title":{"rendered":"Expert Tips for Troubleshooting iPhone 8 Plus Black Screen"},"content":{"rendered":"

iPhone 8 Plus turns on with black screen. What will you start with?<\/p>\n

For screen issues, the most common solution is to replace with a new display assembly to see whether it\u2019s a screen problem or a board issue.<\/p>\n

As for black screen issues, we can also start with the boot current.<\/p>\n

Run boot current measurement first.<\/p>\n

If the boot current is normal, then we can confirm that the phone is turning on with no display.<\/p>\n

As for display issues, find the display connector at the very beginning.<\/p>\n

Related post:\u00a0Samsung Galaxy S6 edge+ Turns On With Black Screen<\/p>\n

Sounds quite simple? Well, follow our repair guide and you can figure it out by yourself.<\/p>\n

Probl\u00e8me<\/strong><\/h2>\n

Press power button to power on. There is no response from the phone.<\/p>\n

Disassemble the phone and disconnect the battery.<\/p>\n

Connect the battery connector with Alimentation en courant continu<\/a> and press power button to power on.<\/p>\n

Current reading on the ammeter is normal.<\/p>\n

Which indicates that the phone is turning on, yet with black screen.<\/p>\n

\"Comment<\/p>\n

Diagnostic<\/strong><\/h2>\n

Since J5700\u00a0is the LCD\/touchscreen connector of the logic board, we need to run diode mode measurement of J5700\u00a0first.<\/p>\n

The measured value of Pin 39 and Pin 45 on J5700\u00a0is 0. Judging by this, the fault is related to relevant circuit of the two pins.<\/p>\n

\"Comment<\/p>\n

Refer to Refox<\/a> – the maintenance drawing and we can see that the two circuits are parts of the screen backlight circuit.<\/p>\n

Now we need to run further measurement of the two circuits. We can start with R5730 and R5733.<\/p>\n

The two are Zero Ohm “resistors” that usually act as protective roles on the circuit.<\/p>\n

R5730 and R5733 are located under the shielding cover.<\/p>\n

For better operating, we have to tear off the shielding paste and remove shielding bracket with Cutting Nipper first.<\/p>\n

\"Comment<\/p>\n

Attach the logic board to PCB Holder and run diode mode measurement of R5733\u00a0and R5730.<\/p>\n

The measured value of Pin 1 on R5733\u00a0is normal and there is no measured value of Pin 2 on R5733, which is abnormal.<\/p>\n

The measured value of Pin 1 on R5730 is normal and there is no measured value of Pin 2 on R5730, which is also abnormal.<\/p>\n

\"Comment<\/p>\n

Judging by this, R5733\u00a0and R5730\u00a0have been damaged and we need to replace with new resistors.<\/p>\n

Conseils<\/h2>\n

As R5733\u00a0and R5730\u00a0are Zero Ohm “resistors”, we can simply replace with new resistors or replace with ferrite bead inductors.<\/p>\n

D\u00e9pannage<\/strong><\/p>\n

Detach R5733\u00a0and R5730\u00a0from the board with Hot Air Gun.<\/p>\n

Apply some BGA Paste Flux to\u00a0the bonding pad. Then apply mid-temperature solder to the bonding pad with Soldering Iron. Once done, clean the bonding pad with PCB Cleaner.<\/p>\n

\"Comment<\/p>\n

Then apply some BGA Paste Flux to\u00a0the bonding pad and align the two inductors to the right place. Solder with Hot Air Gun.<\/p>\n

Once finished, wait for the logic board to cool for 5 minutes. And then clean thoroughly with PCB Cleaner.<\/p>\n

Remontage et test<\/strong><\/h2>\n

Get the logic board mounted first. Then run diode mode measurement of Pin 39 and Pin 45 on J5700.<\/p>\n

The measured value is normal this time. Continue to buckle the display assembly and connect the battery. Press power button to power on.<\/p>\n

\"Comment<\/p>\n

The phone turns on with normal display. Run function test. All going well.<\/p>\n

Outils et pi\u00e8ces n\u00e9cessaires<\/strong><\/p>\n