https://community.nxp.com/t5/Other-NXP-Products/MFRC522/m-p/2182713#M30299 <P><STRONG>Hello everyone,</STRONG></P><P>I am using the MFRC522 reader to read RFID cards and perform a block decrement operation. Recently, I purchased some readers from online shops that turned out to be cloned versions. When I perform the decrement operation, it fails — the command returns a timeout error.</P><P>After that, when I read the same block (configured as a value block through the access bits), I find that the entire block data is corrupted — all 16 bytes are 0xFF.</P><P>Could a cloned RFID reader be the reason for this corruption of the value block?</P> Thu, 09 Oct 2025 05:43:43 GMT RajPadmani 2025-10-09T05:43:43Z https://community.nxp.com/t5/Other-NXP-Products/MFRC522/m-p/2182713#M30299 <P><STRONG>Hello everyone,</STRONG></P><P>I am using the MFRC522 reader to read RFID cards and perform a block decrement operation. Recently, I purchased some readers from online shops that turned out to be cloned versions. When I perform the decrement operation, it fails — the command returns a timeout error.</P><P>After that, when I read the same block (configured as a value block through the access bits), I find that the entire block data is corrupted — all 16 bytes are 0xFF.</P><P>Could a cloned RFID reader be the reason for this corruption of the value block?</P> Thu, 09 Oct 2025 05:43:43 GMT https://community.nxp.com/t5/Other-NXP-Products/MFRC522/m-p/2182713#M30299 RajPadmani 2025-10-09T05:43:43Z https://community.nxp.com/t5/Other-NXP-Products/MFRC522/m-p/2185505#M30370 <P>If the cloned reader has incorrect timing, incomplete command support, or poor signal integrity, it may fail during the&nbsp;decrement operation.</P> Tue, 14 Oct 2025 08:28:17 GMT https://community.nxp.com/t5/Other-NXP-Products/MFRC522/m-p/2185505#M30370 jimmychan 2025-10-14T08:28:17Z