HP DL 360 Gen7 won't start?

Question

Power Supply

Good and knowledgeable people, tell me, please, where to dig?
Server HP DL360 Gen7, 2 power supplies, 2 processors, riser card, additional network for 4 ports.
Entered used server from the warehouse, what happened to him before - is unknown. When you try to start, just fan noise, there is no signal from either the front or rear VGA connector, the back part is also without light, iLO does not glow when connected to the switch. In other words, the BIOS does not start.
There are 2 disks without a backplane in the upper part, 4 disks in the lower part.
When you try to turn it on, there is an increasing noise of the fans, repeated wheezing-clicks are heard from the speaker, nothing on the display panel. I noticed that the built-in network flashes simultaneously with all 4 ports, took it out.
I checked the charge of the CMOS battery - 2.9 V. I put it fresh at 3.5 V
I reset it through the system maintenance switch on the 6 CMOS slider, it seems that it even started to run differently, namely, it blinked once over temp on the SSID in front and silence.
What is characteristic, where there are 8 LEDs on the motherboard at the end of the server - the farthest LED blinks.
I noticed such a feature that the noise is much quieter when only the first PSU is turned on, and the second one is not connected (when the server is off, of course, before the main coolers start). The thought arose that the sensor on the first PSU signals overheating and therefore the process does not go further, I'll try to start it tomorrow on the second power supply.
I will also try to move the sliders 1, 5, 6 to boot from a duplicate BIOS.

Answer 1

Ronald McDonald - thank you very much! Launched the server today.
The following measures were taken: turned off the suspicious PSU, did not start. On the distant ice, everything hung like that. Extracted the memory from the raid, extracted the memory. Still didn't work. I set switches 1,5,6 to the On position - drove for 3 minutes.
After I returned it as it was - I turn it on, a long squeak appeared, but it still did not start. He pulled out the 2nd processor, the RAM, respectively, from his side. And - on 1 processor and 1 bar of RAM, it started.
The first step was to go into the bios and reset it to default. It started a second time ... Turned it off.
I installed the second processor in place, with 1 bar - everything worked. Voila!
Then, in parallel, 1 bar per processor began to increase the RAM. As a result, satisfied, he turned it off, until better times, until the paste is bought in order to normally slobber the processors and leave it alone.
Yes, I have not connected the backplane and disks yet.
Yesterday I didn’t begin to describe that when the upper backplane was carefully connected and the 7th and 8th disks were inserted, with the 5th and 6th disks missing, the transistor on the 6th connector of the bar burned out (I’m not sure if this is a transistor, maybe the conder is a square one like a match head) on the board. I think that a long downtime could have an effect here and you should first turn it on at idle, and then connect the disks, and with the connection order so that you fill 5 and 6 first, and then 7 and 8.
Well, first I drive the server itself after changing the paste, then I connect a couple of disks, then a couple more. And there we can repair the backplane.