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Expert: - 7/2/2011


Question
How to Test if a SIM Card is Bad?

Hi!
We have a similar problem of SIM cards not working after some time (few days / hours) when used in our embedded device.

The device works fine when the SIM card is replaced. And when the spoiled SIM card is inserted in the mobile phone, it shows "INSERT SIM".

Do you have a solution to find the root cause of SIM card failure.

Thanks!

Answer
If you put the SIM card into another GSM phone from your same carrier, it will tell you whether it works or not. Insert SIM doesn't necessarily mean that your SIM card is bad. It may mean that the connection in the phone is bad or the connectors on the SIM are bad. Just put the SIM in anotehr device (same carrier required) and if you can make a call or don't see an error, the SIM is fine. SIM cards rarely go bad and typically, the only issue is when you remove them regularly, they may become damaged. Also, if you have a SIM in a device that is unlocked and is not a tested and approved device from your carrier, the device itself may be frying the SIM card. If the device is approved, it wont' fry the SIM, but I would need to know who your carrier is and what the device to help this a bit further. Hope this helps.

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DebiN

Expertise

I can answer questions on cellular phones, the physical device, the network, contracts, billing, ordering, porting and what to look for when purchasing cell phones. I am located in the United States. I am an expert on BlackBerrys, Treos, HTC devices and iPhones as well as cellphones and aircards. I have over 15 years of experience in both the wireless and wireline world with the carriers. I have a lot of knowledge regarding the wireless providers - their services, prices and policies, both GSM AT&T and T-Mobile) and CDMA (Verizon, Sprint/Nextel). I am very familiar with the individual devices and their specifications. I can also answer questions regarding BlackBerrys, iPhones and other PDAs, both Palm-based and Windows-based. I can troubleshoot most any problem someone is having with their cellular device or with the provider.

Experience

Over 20 years in the Telecom industry working for the carriers with individuals, small business, medium business and large corporations(Fortune 500). Also worked as a professor in Maryland for 10 years teaching telecommunications.

Organizations
I belong to several organizations

Education/Credentials
Master's in Telecommunications

Awards and Honors
Received several awards for papers that I have published over the years

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