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2 Intermittent Cell Signal Issues Persisting After Troubleshooting
Hello All,
To introduce myself I am a professional repair technician who has gone through ISO 9001:2008 certification in mobile device repair with about 1 full year worth of repair experience and 100s of iPhone 6 devices fixed, and this still stumps me.
I know a lot of people have asked about this, but no one seems to be able to give a definitive answer, and I was hoping over the past few months maybe someone has stumbled upon a feasible solution.
We have three iPhone 6 phones in our shop, 2 we own, 1 customer's device all with the exact same symptomolgy: Intermittent service Searching/No Service. At random the device will connect to the towers with good service (3 to 4 bars) and again at random they will switch back to "searching/no service". This issue occurs on all the network types the phone is capable of operating on (AT&T's GSM and LTE and Verizon's CDMA and LTE)
We have confirmed that it is not the following:
-Date and Time are correct
-Toggled Airplane Mode
-Different SIM Card
-Toggle LTE on/off
-Different Network's SIM Card LTE on/off
-Reset Network Settings
-Factory Reset
-No liquid damage
-No apparent frame bending
-Multiple new primary cellular antennas (completely installed new charge ports, ensuring all grounding rings and sticker surfaces were cleaned before installation)
-Multiple new cellular interconnect coaxial cables (the one that runs the length of the motherboard on the device)
-Multiple new upper antenna interconnect flexes (the L shaped one at the top of the motherboard)
-No damage with a continuity reading to all coaxial connectors on the board to their respective pads
I've done what I feel like is a lot of research but keep turning up empty handed. It appears like this issue is caused by a chip on the motherboard that was not underfilled that has cracked or damaged solder joints, I just don't know which one. Logically it must be after the baseband but before the antenna amplifiers, so a switch of some kind? To my knowledge each frequency type/band has its own amplifier (GSM/CDMA/LTE etc.) but they all share the same modem (the baseband). Maybe I'm wrong though, just going on very unclear googling.
I am experienced with board level repair and troubleshooting, and I know it can be like opening a can of worms but I am confident and have nothing to lose in attempting a repair of this kind.
An indepth explanation of both the physical, electrical, and firmware structure of the iPhone's cellular antennas would go a *long* way for me if anyone can.
A little bit goes a long way, if anyone has any thoughts let me know!
Questa è una buona domanda?
3 Commenti
Hi William -
Did you ever figure out what was happening with those 6's ?
I have a similar problem, although trouble started out a different way. My iPhone 6 was drowned in the ocean. It was opened and battery removed and then dried out. From there it was cleaned up and everything worked except the back camera (would not auto-focus), the digitizer (rarely survives water damage) and the battery (also doesn't like getting wet).
After replacing those 3 parts everything seemed proper - the data was even intact. However the cellular connection is slightly weak and intermittently goes to No Service. The battery usage details show that the majority usage is spent on cellular. The WiFi and Bluetooth function perfectly.
Any suggestions on what to try next?
- Many thanks!
da Monte87
Monte, it sounds like you are having a different issue entirely as a result of not only the ambient effects of liquid damage as well as the level of the cell signal. More likely you are dealing with corrosion that has eaten away at one of the grounding contacts for the primary cellular antennas, as you say your battery is getting eaten by your cell signal usually that means it is reaching "further" to connect to a tower. I would make sure that the *entire* phone has been thoroughly cleaned of all corrosion and any remaining minerals first. Then I would check all of the grounding contacts and connections for every antenna on the phone, notably the small one that bridges between the motherboard and the camera retaining bracket as it sounds like that is where a bulk of the corrosion had occurred.
da William Chabot
I have the complete same issue with my iPhone 6 ... 1 week later no random fix working again
da office