1Thank you for purchasing the MSI® motherboard. This User Guide givesinformation about board layout, component overview, BIOS setup and softwareinstallation.ContentsSafety Information ........................................................................................................ 3Specifications ................................................................................................................ 4Special Features........................................................................................................... 8Back Panel Connectors ............................................................................................... 9LAN Port LED Status Table .................................................................................. 10Installing antennas (PRO B660M-A WIFI DDR4) .................................................. 11Overview of Components ........................................................................................... 12CPU Socket ........................................................................................................... 13DIMM Slots............................................................................................................ 14PCI_E1~3: PCIe Expansion Slots .......................................................................... 15JFP1, JFP2: Front Panel Connectors ................................................................... 15M2_1~2: M.2 Slots (Key M) ................................................................................... 16SATA5~8: SATA 6Gb/s Connectors ....................................................................... 18JAUD1: Front Audio Connector ............................................................................ 18CPU_PWR1~2, ATX_PWR1: Power Connectors ................................................... 19CPU_FAN1, PUMP_FAN1, SYS_FAN1~2: Fan Connectors .................................. 20JCI1: Chassis Intrusion Connector....................................................................... 21JBAT1: Clear CMOS (Reset BIOS) Jumper ........................................................... 21JUSB4: USB 3.2 Gen 1 5Gbps Type-C Connector................................................. 22JUSB3: USB 3.2 Gen 1 Connector ........................................................................ 22JUSB1~2: USB 2.0 Connectors ............................................................................. 23JTPM1: TPM Module Connector ........................................................................... 23JTBT1: Thunderbolt Add-on Card Connector ...................................................... 24JCOM1: Serial Port Connector ............................................................................. 24JDASH1: Tuning controller Connector................................................................. 25EZ Debug LED ....................................................................................................... 25JRGB1: RGB LED connector ................................................................................. 26JRAINBOW1~2: Addressable RGB LED connectors ............................................ 26