Hi,
I had a working setup with RePhone + SIM + battery and was able to make HTTP calls etc.
All of a sudden, I have the following problem:
A few seconds after RePhone is powered on, it just switches off. The duration is too short for me to plug-in the USB cable to see any logs.
If I remove the SIM, it works perfectly fine (as in, it stays on, I can flash new application etc.)
The battery is at 4.1V. Nothing else has changed from when it was working.
Any idea what could be wrong?
i have exactly the same problem! please help
Weird question: have you tried in different sim positions?
Also it can have power issues (internal regulator misbehaving) that can’t really be fixed - I heard that providing external supply on 3.3V pins (feeding back) was not enough to use SIM.
Hi manishk11, I know this is no helpfull to you, but how did you made the HTTP calls?, I dont see a gprs library and I would like to be able to send and receive http requests.
Thanks for your time and sorry for my english, not my native language.
Thanks.
I just attempted to insert the SIM in different positions because you asked 
, it gets in only one way.
I am supplying 4.1V to the breakout pin 3 (Vcc) on the side. Is there any test point where I can check the voltage of the output of the internal regulator?
You are right about 3.3V not being sufficient when using with the SIM, I did try that initially and it didn’t work.
@seraphim
I am using the Eclipse IDE (with native SDK) for making HTTP calls (also DNS and NTP calls). For some reason Seeed Studio hasn’t ported the GPRS libraries to Arduino (I am assuming you are using the Arduino IDE). If you have basic understanding of C, it isn’t too difficult to work with Eclipse because the SDK is well documented and has lots of examples. But, of course, you might lose some benefits of Arduino IDE like the already ported libraries 
I just attempted to insert the SIM in different positions because you asked
Man, you got me wrong 
I meant some mm adjustment back or forth - some people had problem with SIM position before (but in that case the SIM was not even recognized) and MAYBE, just maybe it had a small short on the sim.
Is there any test point where I can check the voltage of the output of the internal regulator?
Not really 
Oh! Sorry, I totally misread what you had said 
Fidgeting with the SIM card doesn’t seem to help either. But, I have a feeling you could be right about the short (or something like that) though.
I’ll try and check with another SIM (I don’t have a spare nano SIM lying around, so this could take a while).
Thanks, again.
Don’t you have a multimeter at home? That should be enough to check for shorts. Start with the sim.
i use an regulated power supply, it doesn’t matter. with simcard the problem is still there, but it worked before without problems
i will try to flash it again with Firmware, maybe this works
Didn’t think of that earlier 
. Thanks! But, no apparent shorts.
Did it work when you reflashed the firmware? I didn’t work for me - with both the RePhone native firmware and LinkIt Assist firmware.
no it doesn’t work …to bad
is there no other solution? - seeed guys?
@SeeedStudio guys, any help with this? A new module I bought is lying useless on my table because of this issue. Please help or at least confirm that the hardware has some issue
@SeeedStudio guys, any help with this? A new module I bought is lying useless on my table because of this issue. Please help or at least confirm that the hardware has some issue