Led 1 & 3 light up but led 2 fails

Hi,

I have just put ram sticks in my logic board, the procedure went text book. But im not getting LED 2, fan or chime..

working on a model that has only 4 leds (4 being display connected)

puzzled to where i may have gone wrong.

I can only hypothesise that there is a problem between the PSU and Logic power connections..

What is best way of verifying or checking this? TIA

also,

could someone please confirm the RAM specs for this exact model?, is it possible to have 32gig in this machine, or is that only working on the 4k?

i have put in ddr4 24000 @ 2x16

I notice from reading around that there is a technique to accces the ram slots without disassembly of the logic board.. the model im working on (australian) houses the ram slots in a different part of the logic board.. a little confused why that may be as it is an A1418

.