Chosen Solution
Hi guys, I have an iPhone X here. Original problem is that WiFi greyed out. I set the the temperature of the board separator to 180 degree for a few minutes, then started to a separate the boards. During removal, the upper board accidentally dropped from tweezers to the table while it’s still very hot. I know we should hold the upper board for a few seconds while it’s still very hot, to avoid any chips being disturbed, but the upper board was just dropped from tweezers. Then I decided to test the upper board, sadly it’s dead. Upon further testing, I found lots of lines on upper board are shorted (pp0v8_soc_fixed_s1, pp0v6_vddql_s1, pp_gpu, etc. are all shorted)! I checked upper board, it looks clean, I didn’t see any chips disturbed by the drop. I already used freeze spray, but couldn’t find any bad components in all the shorted lines. I don’t know where to start at the moment. Any help would be appreciated. Thanks.
I doubt very much these lines are shorted. These are very low resistant lines so if you had your multimeter on continuity mode they would indeed beep. Also 180 degrees would melt the balls on the interposer board but would not be hot enough to cause bridging under any IC. Continue with your original repair. I usually just remove the top board and check for oxidisation or cracked solder balls then put it back on with your heater. This most likely will bring back the Wi-Fi if not you are in for some pain.
I saw Jason at sts telecom put a screw in partially and use it to lift off the top board to separate it. I’m I can’t help you currently but this might keep it from happening again.
