Today I'm gonna introduce you guys how to repair an
iPhone 4s No wifi issue , which I learnt from a professional touch. The reason I post this is attracting more people who fancied and interested in cell phone repair. I'm not a professional one , I just stepped in this area this year , and really wanna make more friends. (English is not my native, so plz understanding
)
iPhone 4s NO wifi
No Wifi issue: means wifi turns gray , Bluetooth doesn't work and No Mac address in "About" bar..
Let's take a look at the iPhone 4s schematic find out what will cause No wifi issue.
There are 3 conditions IC need to running.
1.VBAT(battery)
2.Reset
3. 32.768 Clock(quartz crystal)
Lets see the schematic below . pin 27 pin28 is VBAT also know as B+, pin12 is reset, pin 47 is Cock , We should test (1) C68_RF B+3.7V (2) R95_RF 1.8v (3) PP13_RF 32.768
![168079898.png]()
We can test (1)(2) with multimeter ,every one can easily get it from radio shack or home depot, but if u wanna test (3) you have to get a oscilloscope thats not a local hobby store stuff. Its professional only. We can skip this step.
the voltage marked below if from normal iphone 4s.
![68079898.png]()
![Unnamed.jpg]()
Speaking of (1)(2), if both of it working great (on right voltage), It might be (3) or wifi component ,But we can't test (3) The wifi IC LDO voltage will be the only one we can test. we can get wifi LDO voltage through C136_RF ,if u can't got the 1.2v or the voltage is too high that means wifi IC not working. lets see where we can find the C136_RF
![65E029898.png]()
PS. C136_RF is under the shield
![65E068079898.png]()
So if B+,RESET and wifi ic all working great then the Clock might be down.
If B+ RESET and Clock no problem, it means you have to replace a new Wifi Chips .
![39898.png]()
Desolder the chips and clean the board,put new solder to the pin and solder the new chip back .(heatgun needed)
PS: Don't rip off these two tiny 10k Pull-up resistors ,I don't know what's this for but WIFI won't working without two of this.
If anyone needs schematic and component placement map of iphone 4s ,plz text me or email me eben.public@gmail.com.
iPhone 4s No wifi issue , which I learnt from a professional touch. The reason I post this is attracting more people who fancied and interested in cell phone repair. I'm not a professional one , I just stepped in this area this year , and really wanna make more friends. (English is not my native, so plz understanding)iPhone 4s NO wifi
No Wifi issue: means wifi turns gray , Bluetooth doesn't work and No Mac address in "About" bar..
Let's take a look at the iPhone 4s schematic find out what will cause No wifi issue.
There are 3 conditions IC need to running.
1.VBAT(battery)
2.Reset
3. 32.768 Clock(quartz crystal)
Lets see the schematic below . pin 27 pin28 is VBAT also know as B+, pin12 is reset, pin 47 is Cock , We should test (1) C68_RF B+3.7V (2) R95_RF 1.8v (3) PP13_RF 32.768
We can test (1)(2) with multimeter ,every one can easily get it from radio shack or home depot, but if u wanna test (3) you have to get a oscilloscope thats not a local hobby store stuff. Its professional only. We can skip this step.
the voltage marked below if from normal iphone 4s.
Speaking of (1)(2), if both of it working great (on right voltage), It might be (3) or wifi component ,But we can't test (3) The wifi IC LDO voltage will be the only one we can test. we can get wifi LDO voltage through C136_RF ,if u can't got the 1.2v or the voltage is too high that means wifi IC not working. lets see where we can find the C136_RF
PS. C136_RF is under the shield
So if B+,RESET and wifi ic all working great then the Clock might be down.
If B+ RESET and Clock no problem, it means you have to replace a new Wifi Chips .
Desolder the chips and clean the board,put new solder to the pin and solder the new chip back .(heatgun needed)
PS: Don't rip off these two tiny 10k Pull-up resistors ,I don't know what's this for but WIFI won't working without two of this.
If anyone needs schematic and component placement map of iphone 4s ,plz text me or email me eben.public@gmail.com.