I bought a used iPhone 4, originally from the UK (now in Denmark). The phone has been reset/restored, updated to 5.0.1 and appears to be functional with 4-5 bars and the "3G" icon next to them. The phone worked perfectly with the previous owner's SIM card.

However, all outgoing calls fail immediately with a "call ended" message, incoming calls produce a two-tone at the caller's end and texts can not be sent, yet data works over 3G. Strangely, I have made 1 outgoing call while connected to iTunes, but a second attempt failed. I am experiencing this using a known-to-work SIM card from another iPhone.

In Xcode, the console produces these messages when trying to make a call:

kernel[0]: computeProxBaseline.. This is a negative slope unit
kernel[0]: computeProxBaseline.. This is a negative slope unit
kernel[0]: This is a negative Slope unit. Going to use a fixed power of 3. This will behave like an Apex unit

Googling for this only revealed this unhelpful pastie: http://pastebin.com/q8vMQvpv

So, the phone or text is not working but data over 3G is.

Any suggestions?

  • The exact same problem here, also in Denmark btw. Could this be an issue with our provider? Any advice would be appreciated.
    – user15454
    Dec 23, 2011 at 14:36
  • 1
    Really seems to be a provider issue, since it was working with the previous owner. Did you try to contact your phone provider? Can you and anon tell us which is your provider? The provider of the previous owner? Dec 23, 2011 at 14:48

1 Answer 1


The phone was replaced free of charge with no clear explanation of what was wrong. The replacement, however, would indicate that it was not a software/firmware issue.

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