AsRock x870 Pro Wifi not booting

Make sure the RAM is all the way into the slot, new slots can be very stiff.
Both RAM and CPU lights being lit usually means an issue with either RAM or CPU.
Most often that the CPU isn't supported on the BIOS version installed but I don't
think that is the issue in your case. The RAM not initializing is preventing the
POST process from completing the CPU tests most likely. If the RAM light is yellow
not red then I would guess it is passing some of the initial tests and failing
part way through the RAM POST tests.

If after ensuring the RAM is fully seated you still have the issue then you should
try another kit of RAM to rule that out. It is also possible you got a bad CPU
but that is far less likely than faulty RAM.

By bank 2 and 4 I am assuming slots A2 and B2 (should be labeled on the board).
If so, that is correct. Make sure you have the correct 8pin CPU power connected,
typically, when there are 2 sockets on the board I connect it to CPU power 1.

Your BIOS version should be printed on a small white sticker on your BIOS ROM chip
on the motherboard itself though it should be at least version 3.06 anyway given
there is no earlier version available so that shouldn't be the issue.

Once you have gone over all the power connections and made sure your RAM is properly
seated in it's slots you can try powering on the system again and let it remain
on for 5 mins, don't restart or reset, just let it run. If you don't POST still
then try removing the RAM from slot B2 and test with a single stick in A2. If
that fails try the other stick in the same slot.

Post back here with your results. Good luck