Please ensure the power adapter meets requirement below and test the board out of chassis with just the memory installed, no other device attached. If the power adapter meets requirement below and yet the board doesn't power up, the issue may be some thing else. Let's verify this one first.
External Power Supply
– the board can be powered with an 8-19 V DC external
power supply though the DC jack on the back panel (Figure 13, A). This connector
accepts dual-barrel plugs with an inner diameter (ID) of 2.5 mm and an outer
diameter (OD) of 5.5 mm, where the inner contact is +8 V DC (±10 %) through
+19 V DC (±10 %) and the shell is Ground. The maximum current rating for this
connector is 8 A.