Method to Resolve Samsung Galaxy S3 SIM and MMC Problem

[AnDRez]

Problems

Sim card problems

Following are some of the common Samsung Galaxy S3 Sim card problems:

• Sim Fails to read
• It shows the error “Insert SIM Cardâ€￾.
• Sim not reading properly.

MMC problem

Following are some of the Samsung Galaxy S3 MMC problems:

• MMC not inserted
• Card corrupted
• Fail to read
• Hanging problem while inserting card.

Reasons of Problems

For Sim Card

• Sim card might be out of order.
• Sim contacts are not able to make proper contact with Sim card jacket’s contacts.
• Sim card or card holder pins might be dirty, clean both of them and check.

For MMC Card

• MMC might be faulty or the content of the card might be corrupt.
• Viruses or bad sectors in MMC might also be the cause of this problem.
• Any of the hardware components might be faulty.

Workaround

For SIM Card

In order to resolve all these problems, all you have to do is to follow the following steps:

• Use any other good sim card in your Samsung Galaxy S3
• Visually check SIM card holder for possible damage and also clean it

For MMC Card

• Use any other good MMC card, if the second one works fine then it means the previous card was faulty.
• In case the message is something like “Memory Card Corrupt, need to formatâ€￾ then it means that your memory card has viruses or bad sectors, and you need to format it in order to get it working.

Hardware Solution

For Sim Card

• Fix all the misaligned pins or you can also chose to replace PCB holder too.
• Check SIM voltage when the SIM card is inserted, it should be around 1.8v.
• Trace every VSIM, SIM reset, SIM clk and SIM IO and Ground pins (as shown in above Figure)
• Pin details as mentioned in above figure (from top right) includes: pin2 ground, 3 VSIM, 4 sim clk, 5 sim data.

For MMC Card

• Change MMC PCB strip and reinsert memory card and check whether it is working or not.
• If MMC is still not working then re solder MMC board connector
• Reheat or replace MMC IC which is mounted at top right of MMC/SIM connector this is surely going to resolve the problem.