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I have a device (XT107) that requires a SIM card. It takes a SIM card that have cobber plate (not sure what to call that) that supports all 8 curcuits on the device.

enter image description here

When speaking with people, some say it's a 2G SIM card, but I doubt that since some of my friends have a HTC Desire which uses this kind of card.

Mini sim card - 4 pins - (8 circuit):

enter image description here

Mini sim card - 3 pins - (6 circuit):

enter image description here

What are the differences between these two cards above? I'm really lost here. I need that one with 4 pins(8 circuit), but when speaking with the mobile phone companies' tech support, they are totally lost.


I have added the real names for the simcard to the above, but still maintain the original question with names etc.

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Here are the first missing link to the XT 107 device: i.stack.imgur.com/zAXjI.jpg – Syska Jul 2 '12 at 12:15
That's not a 4 pin connector, but an 8. The horizontally opposed pairs of contacts are separate circuits. Outline looks to be for a standard full-size SIM card, though the micro may work if it can be reliably mechanically positioned. And it looks like there's a separate micro-SD socket underneath to the right. – Chris Stratton Jul 29 '12 at 16:39
Yes, theres support for a Micro-SD. As a other said the 2 extra curcuits are almost never needed, but it seems it is in my case. But the question is, what other pins can I short-circuiting it to? – Syska Jul 29 '12 at 22:19
You should not modify it at all. The larger card, which you mistakenly label "4 pins" actually has 8. – Chris Stratton Jul 30 '12 at 1:37
Yes, but the problem is that I have the 6 circuit sim-card, which dont have the extra pins. – Syska Jul 30 '12 at 11:41

All 6 pin or 8 pin have the SIMs have same functions.

At first we need to understand SIM Pinouts;

6 pin includes VCC, GND, I/O, VPP, RST, CLK

8 pin includes VCC, GND, I/O, VPP, RST, CLK, SIM_PRESENCE, GND

VCC is supply pin, GND is common ground pin, CLK is Clock pin, RST is Reset Pin and I/O pin is for Data transmission.

The only difference between 6 pin and 8 pin is of SIM_Presence pin, The is an optional pin of SIM, and their are two GND pins on 8-pin sim.

For you device you may use 6 or 8 pin SIM, as SIM_PRESENCE is not necessary required.

The only useable PINs for devices are VCC, GND, I/O, RST, CLK. Hope this will may help you

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Hmmm, SIM_PRESENCE or GND seems to be required ... since it works with 8 circuit SIM cards. Can I short-circuiting it somehow? If, which other pin can I connect it to? The unit just keeps blinking which means it need either SIM_PRESENCE or GND. – Syska Jul 29 '12 at 22:15
SIM_PRESENCE is sometime required and some time not, I had designed my own circuit for a project using the GSM module which is also present in your device, it is SIMcom SIM900 or whatever number. It worked with both SIM_Presence and no SIM_PRESENCE, If you want to short circuit it than you must insert a resistance in between SIM_Presence and VCC or GND pin, resistance value should be more than 500 ohm, as SIM voltages are 1.8V. – masterleous Jul 31 '12 at 7:15
For a non-electrician guy. Can I short-circuit it somehow? Either to GND or VCC? – Syska Jul 31 '12 at 7:17
hhhmmm thats difficult, what type of blinking you are seeing? either it is blinking for a short period of time within a second or it is blinking once in more than 2 or 3 seconds? – masterleous Jul 31 '12 at 7:38
The green in the middle is blinking which is power indicator. The yellow LED is also blinking which means is has GSM issues(I guess it means that it can't find the SIM, because it don't work. When I use a 8-circuit sim its stays yellow all the time. However that was a friends SIM-card so I can't use it permanently. The 3 blue LED does not start flash until it has a working GSM signal. – Syska Jul 31 '12 at 7:50

What size is the holder, could it be that the sim the device requires is a mini sim (the Telia one you show looks like a micro sim with a mini sim adaptor; the Telenor mini sims I have been able to look at all have 8 circuits)?

A mini sim would be 25x15 mm, a micro sim 15x12mm.

btw Molex calls the connectors on the sim circuits, not pins.

share|improve this answer
Yes, I know that these are Mini SIM and Micro SIM. So, I need a SIM card with 8 curcuits. As seen on the first picture of the XT 107, that's what it requires. I'm sure I need a mini sim to get the 8 circuits on the card. I just need a name for such card. – Syska Jul 2 '12 at 12:48
huh? the name of that sort of card would be "a 8 circuits mini sim". i would find a physical store to visit with the device and sort it out that way, but that might not be an option? – Jontas Jul 2 '12 at 12:58
Well ... I have tried. www.3.dk told me it was an old "2G mini sim" that I needed and that they have never had that. I have company paid phone and "data sharing" so I get 2 additional sim card. So I would prefer if I could actually get the SIM from them, instead of paying another company for a SIM card that I rarely use. That's why I need it, but I think I need do did a little deaper. – Syska Jul 2 '12 at 13:26

A similar question was already answered here.
On the 8 contact SIM card 2 of them are reserved for future use. I can't tell if in the card on your picture they are used on not.

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Bruno, this is considered a bad answer. If that link dies your answer becomes useless. Please summarize here, or your answer may be deleted. – stevenvh Jul 2 '12 at 12:32
I'm still not sure what the name is calling the mobile company. Yes, its a mini simcard and it has 8 circuits. – Syska Jul 2 '12 at 12:52

The Grameen card bears a telenor logo and looks exactly the same as a telenor card in Sweden, where norwegian Telenor is a major operator. That card appears to be an 8 circuit card. The latest Telia cards don't look the same as the one on the photo but it appeas that it is still a 6 circuit sim card. These cards should be interchsngeable and I know that both the 8 circuit telenor card and the 6 circuit Telia cards are recognized as present in a German AVM LTE router which has a 6 contact sim reader.

I need to find out the order of connectors for a 6 contact sim card reader. The sim card holder I need to use to replace a damaged card reader as three contacts on each side. When the mini sim card is put in place looking down onto the contacts, the cut off corner is on the upper right hand side and I see the back of the card. Placed thus, it appears to me that the order is the following, starting from the cut off corner: 1 VCC, 2 RST, 3 CLK, 4 GND (top on left side), 5 not used, 6 I/O.

Could this be correct?

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