Why won't my computer start with new RAM?

Question

motherboards

There is an ancient computer with a GA-H55M-S2 mother (rev. 1.3), an Intel Core i3 540 processor and a new Hynix 8Gb PC3-​12800 1600MHz DDR3 DIMM RAM (I bought it here ).
But after installing it, the computer stops at startup after the line Memory testing: OK and cuts down, then reboots and so on in a circle. Can anyone tell if the RAM is compatible with the computer and what else could be the problem? When installing the old two strips, everything works again.