I had this same problem. The Red Light not appearing is due to a few possible reasons:
1.) The cable that is connected from the Power Button/Eject Board to the Motherboard is broken (I had this once)
2.) The Power Supply Unit (PSU) is dead (maybe the fuse blew)
3.) The ribbon from the Blu-Ray Drive is not connected.
4.) The Power Supply isn't connected to the motherboard.
5.) The console may not have enough power or is overheated (3 beeps)
I would order a new cable (1st reason), ask someone if their power supply unit works and if you can use it. Make sure Blu-Ray Drive ribbon is connected and not broken. Make sure PSU is connected to motherboard properly. Also check if the thermal paste is dry, etc. You should get what I mean