Hello all!
I'm trying to fix an iPhone 4 16Gb with several problems. I manage to fix easily all of them but the "No service" is still there. After enter SIM pin it remaing switching beetwen "Searching" and "No service".
Emergency calls gave me a "Call error" so I was pretty sure there was not signal coming from the antena.
First I tried the most obvious, check the antenna conection and try with another antenna, no luck...
Then I tried another SIM (just in case...).
Then i start looking into the Logic board:
The capacitor C95_RF is not there and it seems never was but even if it was removed I don't think is enough to avoid the signal completely (in fact in the 4S this one is not there...). I checked all the way to C303_RF and seems to be ok but there's something I don't get. Looking at the schematics from J9_RF to R3_RF there's nothing grounding the signal but I'm getting a nice continuity to ground in all the path. If R3_RF is a 201 ohm resistor I should get something like this when measuring from GND to the antenna input (the other side or R3_RF is filtered to GND with a coil).
So, anyone can tell me how it should be before remove the R3_RF (cause is the next I plain to try)? I'm right or the antenna input have to be grounded all the way?
Any ideas?
Thanks a lot in advance and sorry for the "home made english" :)
I'm trying to fix an iPhone 4 16Gb with several problems. I manage to fix easily all of them but the "No service" is still there. After enter SIM pin it remaing switching beetwen "Searching" and "No service".
Emergency calls gave me a "Call error" so I was pretty sure there was not signal coming from the antena.
First I tried the most obvious, check the antenna conection and try with another antenna, no luck...
Then I tried another SIM (just in case...).
Then i start looking into the Logic board:
The capacitor C95_RF is not there and it seems never was but even if it was removed I don't think is enough to avoid the signal completely (in fact in the 4S this one is not there...). I checked all the way to C303_RF and seems to be ok but there's something I don't get. Looking at the schematics from J9_RF to R3_RF there's nothing grounding the signal but I'm getting a nice continuity to ground in all the path. If R3_RF is a 201 ohm resistor I should get something like this when measuring from GND to the antenna input (the other side or R3_RF is filtered to GND with a coil).
So, anyone can tell me how it should be before remove the R3_RF (cause is the next I plain to try)? I'm right or the antenna input have to be grounded all the way?
Any ideas?
Thanks a lot in advance and sorry for the "home made english" :)
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