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bole5
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iPhone constantly searching for carrier (no service)

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Hi,

I dropped my iPhone and now I get "no service".

When the phone boots up (or after switching the airplane mode on and off) it finds the signal (at the weakest level) but after 10 seconds, signal is lost and the phone is searching for the carrier again...

Everything else works normally (Wifi, etc), and I can use it as a "skype" phone, listening to music and surfing.

My OS is 3.1.2 (with 05.11.07 baseband)

I tried the following (without success):

  • doing full restore with DFU mode on clean iTunes
  • opening the iPhone and making sure no cables are loose
  • 3G is switched off

Does anyone have any advice what else I could try?

Edited by: rj713, oldturkey03, and machead3 ( ) , bole5 ( )

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markus weiher
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if the sim card is properly in it's place - then you should read the following ;-)

since the phone is getting a weak signal and loses the signal within a few seconds - i would say that there is a problem with the antenna area (connectors/antenna)

if it would have full reception - but loses the signal within 5 to 10 seconds - it would normally be a defective power amplifier or a broken antenna switch (most likely the switch would die first when a phone is dropped)

the "no service" message in those two cases is normal(!) - the phone receives the signal but the bts (Base Transceiver Station) does not recieve a signal from the phone (something like a handshake) - so it does not "lock" the "cell" to the phone and goes on - it simply doesn't see or hear the phone - and that was the short explanation why you get the "no service" message

but what now ?

if there is nothing to see from the dropping and the phone is still under warranty - go to apple!

if not, open the phone and check the connector between the dock conector ant the logic board - maybe it's slightly dislocated

wut you wrote that you checked the connections - that could mean that the antenna is defective - but check everything again - checking is better than buying a new part ;-)

here is the guide for the dock connector

Edited by: markus weiher ( )

Thank you very much for taking your time and helping me with this problem. The SIM card contacts are surely OK, the connector between the logic board and dock connector is also OK. How can I check if the antenna switch is broken, or alternatively how can I check that the power amplifier is defective?

bole5,

checking the switch is mostly not that easy possible, if they are broken - the parts will fall apart while desoldering (with hot air) - but normally the parts stick on their solderpoints - but betwenn the points can the switch be broken, if the pa is broken you can't check that either - normally there are a few different tools to measure the pa and switch. without the probper tools is there no way you could fix that by yourself - sorry. but since your problem is a little bit different, i would first try to change the antenna.

markus weiher,

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Nat
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I had exactly the same problem with iphone 4.

This is what I did:

1. sync and backup phone on itunes

2. settings - general - reset - erase all content and settings

3. set up phone again using itunes backup

It did the trick!

Goodluck

i did the reset and it worked very very happy becky

becky,

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rab777hp
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Try checking if the sim card is in right, it might be not properly in it's place, use this guide to guide you.

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voxleo
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There is a TEENY TINY inductor on the motherboard which is apparently very easy to knock loose of the soldering and therefore breaks the antenna circuit if is dislodged, I would look at that if a software solution is not helping. Most of us doing first time repairs were entirely unaware we'd lost it most likely when we first removed the motherboard's last screw under the "Do not remove" warning tape. I had no idea why my new screen worked so beautifully but I had a whole new problem of "no service"! I tried everything and found no solution until this (thankfully someone figured out what no one else had)

Check for this component either missing or loose and/or damage to circuit traces in this area. Also check that the dock connector piece hasn't come apart at the seam and lost the spring loaded pin which is supposed to contact a small pad on the motherboard - too tight screws or the wrong screw can cause the board to bend just enough to break that contact because it lifts away from the pin also.

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ormatej
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Maybe this will help someone, or bring us closer to solution.

Hey, I have similar problem. Iphone 4 looses carrier randomly, normaly after few hours. If I just reset it, it doesn't help.

However, what helps is this: I wrap it in a plastic bag or plastic foil for food and put it in a deep freezer for a hour or so.

Then I take it out of the freezer, wait few minutes that it warms up a little (this is the critical part for moisture ---thats why it is in a foil) and then power up and it works for another few hours.

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Ronan
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hi all

I dropped my 3gs this morning and it went searchingall day ,When I power down it would come on wit 1 bar for a minute and then searching

again Reseated the sim and exact same ,all this time the WIFI connection worked to my wireless lan.

I tried my sim in my work phone and bingo no service

then put my work phone sim in my Iphone and all worked immediatly.

No logic bt ssim broken in fall not phone problem at all.

Hope this helps some of you

Ronan

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Jami
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hey guys, i had the same problem on my wife's iphone 3gs, i tried so many ways but nothing, i took it to a store and he fixed it for a 20$.. but again i had the same problem today with my iphone 3gs, but i google for a help and here is what i got and it worked perfectly :

"Use old SIM card, putting the old SIM card in the iphone (respring) then remove it and replace it with ur SIM and here it goes working again"

hope it works with u guys it worked for me.. best wishes and good luck.

Jami from lebanon

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Elizabeth Augenstein
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hi, here is what can be done to rectify the problem..iphone like any other phone is fragile....one need to be careful with it always....since your iphone dropped the possible problem that arrive from it is that..your iphone must have loose which cause no service problem..since sometimes the sevice we show up and later dissapear..look for a tech that knows well about the iphone and let them loose the iphone to the back side and tighten up any loose part....am sure this would work.

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johnkustic
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Sounds like you Blue inductor got damaged. Check your motherboard if the blue inductro is damaged or missing.

See the picture below.

Block Image

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Hani
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i have the save problem in UAE, the problem comes from the LTE network.

the problem solved as the following:

1- make factory reset and complete format

2- after formating and while activating your phone , you will get message from your carrier saying that there is a carrier network update, this update is for the LTE .

Don't update the carrier and keep using normal or 3G, then the problem will solved.

note:

before update you will see you mobile like this:

setting -general - cellular - cellular data & Enable 3G.

after :

setting -general - cellular - cellular data , LTE, .......etc.

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Jimbo
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After taking a dip in the pool, I was stuck in the Searching... mode for a day. Everything else worked on the phone. I tried rebooting. No go. Came to this site and attempted to try the "back up iphone and reset all settings" While backing up the phone, I decided to put a the phone next to my portable heater.

When I connected to iTunes, it was waiting for the ios 6.0.1 update so I decided to update. It was under the heater for about 10 minutes and after the reboot of the phone after upgrading, the phone works now. Hope this helps someone.

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Abhi Sharma
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iPhone no service error 100% fix in 5 minutes

I had this issue for about 1 month & i went through everything- Googling,yahoo search & apple discussion.

At last I have fixed my iPhone4 in 5 min.

First of all u need to know if it a software or hardware issue-

1. Toggle airplane mode for 4 seconds & wait for network.

2. Reboot iPhone.

3. Network reset.

4. Manually choose network.

5. Hardware repair method-

(Switch off your iPhone & take out the sim tray before continuing)

Take out the 2 screws from the bottom near the speaker mesh. Slide up the back panel & take it off.

Now take off the battery by taking off the little screw on the battery terminal.

You will find a very thin black wire near the battery terminal with a small plate on its end.

Near the terminal stand u will find a place to fit the plate. First clean the plate with a cotton cloth gently.

Connect plate on its place it & press it a little till u hear the little sound- tick.

(*Remember not to press so hard*)

Connect the battery & put the screw back. Get the back panel again & put the bottom screws.

Yippee..!!! U have fixed the annoying- NO SERVICE error on iPhone 4.

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