Why won't the system start?

Question

Iron

PC Config: AMD Athlon II X2 240e (standard cooling), Kingston 8Gb DDR3 1600 memory, Asus M5A97 Evo R2.0 mother - BIOS 2603, Nvidia GTX 650 video, 500W Chieftec CTB-500S PSU 85+ efficiency, SSD, HDD, drive, 3 coolers.
I bought a used AMD FX-8120 processor, I install it with Zalman CNPS10X Optima cooling, I turn on the computer and the screen is dark, the BIOS does not start and the CPU LED is on. I thought maybe there was not enough power, I checked it on the website outervision.com/power-supply-calculator , it should be enough based on calculations. What could it be?
Update: Bought an AMD Phenom II X6 1045t today, same story. Does not turn on. I tried on another ASUS M4A88T-V EVO / USB3 motherboard, the same thing (

Answer 1

1. turn off everything except the mother and check.
2. connect the speaker or what kind of signaling from the motherboard is there - what does it write / how does it squeak?
3. if there is complete silence - the legs of the processor may have oxidized - try to clean it with any antibacterial solution (but not with a solvent!).
4. Check the power supply and power supply to the video card.
5. Reset the BIOS with a jumper.

Answer 2

Is the processor compatible with your motherboard? it may so happen that due to the difference in those manufacturing processes, they are not the same

Answer 3

Are all cables connected to the motherboard?
Prots obviously working?

Answer 4

standard set of actions for jambs with loading
0) check for the presence of cables in the power connectors.
1) reset bios.
2) disassemble the computer completely.
3) assemble the minimum configuration for starting - a processor with a cooler, 1 ram, a video card, a PSU motherboard and a monitor. (Even a keyboard is not needed)
4) if after that it does not start, you need to find out which of these five has died, if possible, replacing parts
in your case the most likely three options are a
dead cpu, a half-dead mother, a half-dead bp.
half-dead is when weak equipment pulls, and what does not pull more powerfully.
there is a non-zero probability that the capacitors on the motherboard or (and) the power supply have dried up, in order to check this, you need to take it from someone to drive the power supply with the motherboard.
in principle, you can get by with a soldering iron with a donor motherboard / video card, but you need to clearly know what to do.