Check the URL printed at the bottom of your card. Common official sources include r4i-sdhc.com or r4isdhc.com.
This guide covers everything you need to know about setting up, updating, and bypassing common issues with the 2015 Dual Core kernel. 1. Identifying Your Card r4 sdhc 2015 dual core firmware
The standard kernel for most 2015 Dual Core cards. You can find archived versions on sites like RetroGameFan YSMenu: Check the URL printed at the bottom of your card
The 2015 Dual Core almost always has a spring-loaded microSD slot (push to click in/out). Earlier clones often used friction-fit slots. r4 sdhc 2015 dual core firmware
Usually a sign of a bad contact. Clean the gold contacts on the back of the R4 card with a pencil eraser or isopropyl alcohol.