iFixit EU Team
"Screen is black but I can feel it vibrate"に関する回答Hello Zero, if you opened the phone, there‘s the possibility that the display connector isn’t plugged in properly or you damaged the display by accident during the opening procedure. Try to open it another time and control if the connector is plugged in properly. You can check if the display is working before reapplying the back cover with anew adhesive. In case I didn‘t get you right, and you did not open the phone, it is likely that your display is broken because of water damage or similar. In this case, you need to replace the screen. The vibration motor is still working because it isn’t connected to the display but to the daughterboard.
"I inserted the pin in the left bottom microphone"に関する回答First image shows the two bottom holes in the frame in yellow. The gaskets for the microphones are marked in red and sit on top of the holes in the frame. In the second picture you can see the two microphones (marked in orange) which sit on top of the two small daughterboards. Under the microphones there’s a small hole in the daughterboards which connects to the gasket. Because of this build i don’t think it’s possible to puncture the gasket or the microphones.
"I inserted the pin in the left bottom microphone"に関する回答Hello Enrico, I just opened the Mate 20 Pro and what i can say is this: There are two microphones at the bottom end of the phone. I can’t tell when which one is in use but both of them sit on top of small daughterboards. So the gasket for water- and dust proof isn,t placed at the end of the small holes but on top of it. The rear end of both holes should be plastic of the mid frame. In my opinion I don’t think it’s possible to break one of the gaskets by entering a pin in one of the holes but i can’t give you a guarantee for that.
"Huawei Mate 9 PRO's screen is broken and looking for ways to replace"に関する回答Hello White Butler, usually it is less expensive to replace the display on your own. Regarding to your question on the screen and touchscreen digitizer - it depends. What is exactly broken? In some cases the touchscreen and display both still work and only the front glass is broken. In this case it is enough to replace the front glass but you will need new adhesive for it and i can become complicated to repair and not to damage the display itself while doing so. There is danger to get bubbles between display and glass as well. But overall the front glass on its own is a lot cheaper than the display and or touchscreen of course. If you want to go with the display or with the display with frame, it depends as well on what exactly is broken. If you want to replace the display without frame, usually you just need to take the battery out before you can replace the display. If you want to install a new display with frame, you need to transfer every component of the old phone to the new frame (motherboard,...
"Cannot hear any Sound on my phone"に関する回答Can you hear any other sounds on your device e.g. from videos or something? If not it seems like your microphone works but your loudspeaker is broken and needs to be replaced.
"Battery percentage stalls when plugged in"に関する回答At first you can reopen the smartphone and make a double check if the battery is connected correctly. Same goes for the LCD (another issue could be the connection of the charging board to the mainboard - you can check this as well). It also can happen, that you damage the interconnect flex cable between charging and main board, whilst removing the battery, in this case the phone wouldn't charge as well).
"Why does can't I sigh in in youtube and play store?"に関する回答First thing to try is to reinstall the apps. If they're pre installed and you can delete them try a default reset of the phone after saving all your data. Do your usual Updates afterwards.