Chosen Solution
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!
If all bands and cellular services fail intermittently, maybe you should take a look at the baseband, baseband power supply and/or transceiver. If these chips have intermittent failures, the entire cellular function also fails intermittently.
I reached out to Jessa at iPad Rehab and she believes that the BGA on the Baseband Chip is failing and that it would need to be reballed. She said that it was a staple failure on the iPhone 6 series. This process would be similar to that of the Touch IC except since that the Baseband is married to the motherboard it can not simply be replaced it must be reballed.
Hi, the problem is caused by the baseband IC chip. You can double check this by dialling *# 06# If the screen is blank then its this chip. If the IMEI comes up (it will only show when you have a connection to the network), then its this Baseband chip. Checking under general settings will always show the IMEI even if the baseband chip is faulty. The phone get bent a little in usage and back pockets, which breaks some of the solder connections under the chip. The only way to fix this is to remove the chip, clean all the old solder off, then reball/solder and refix the same chip which is married to the board. Trying to heat the chip and giving it a nudge will not work as you need to repair 2 specific solder points which will have already been cracked and damaged. This is a very skilled and specialised repair. Hope this helps. KH
I have a theory as to what could be causing this issue as it is happening on my 6 plus too, all the hardware seems perfect and all software fixes have been tried. I have noticed that the loud speaker module is acting more magnetised than normal at the bottom of the phone so much so that the magnet can pick up objects through the screen, something which I had previously not noticed. With a strong enough magnetic force in the presence of the cellular antenna hardware connection at the top of the loudspeaker connection this could be causing signal interference on the cell antenna. I do not have parts currently to test to see if this is in fact the cause unfortunately but this could be the cause.
why is my cell phone slow to respone whenI type a word its takes time to appear? LGK40 PHONE THEY SAY ITS AN OLDER PHONE? IS THAT CORRECT?
