SIM800C developer board "SIM not inserted" I bought this SIM800C development board (vendor unknow):




I conected it to an Arduino and put a brand new SIM card in it. This is the model of SIM I'm using:



Problem is, development board doesn't detect SIM card:

at+cfun=1,1    
OK
at+cpin?    
+CME ERROR: SIM not inserted
at+csmins?    
+CSMINS: 0,0


This is the scenario: 


6 pin SIM in a 6 pin SIM card holder.
SIM works fine in a cel phone. Send/receive voice call/sms.
Older, working SIM from various providers doesn't get detected either.
Every other non-SIM related aspect works.
No reboots, no flickering.
Board takes care of regulating voltages and signal levels.


I put an oscilloscope probe on the SIM_VDD pin (against board ground) and got this on every power-on:



Two 1.8v and two 3v pulses. That's all.

Please, note that I have no access to all SIM connexions (multi layer PCB).

How do I solve this problem?
The print on the PCB and product description at sellers site states it is GSM/GPRS board. The  module on the board comes from SIMCom. This particular SIM800 module seems to have following capabilities as per SIMCom:


Compliant to GSM phase 2/2+
GPRS multi-slot class 12/10
Quad-band 850/900/1800/1900MHz


I think at the best you can only use a 2G SIM card on this board. Any 3G/4G SIM will not work.

Thanks for those images in the problem description, it gave me relevant keywords to search.