Old Geezer's PC build is DOA. What to check/look for initially?

[Mister Ed]

Howdy,

I am an "over the hill" retired boomer who got the crazy idea to build another computer after ten years of using my current Linux based PC.
I purchased the following new bits & pieces:
Core V21 Micro ATX case by Thermaltake.
ASUS PRIME H570M-PLUS Motherboard
Antec NeoECO Platinum 850w power supply
Intel CORE i5-10400 CPU
Two G. Skill Ripjaws V DDR4 memory modules
Seagate 250 GB harddrive

I am not a gamer so please give me a break on my product selection. LOL
Symptoms: Turning on power supply (outlet supply voltage verified) and pressing boot button on case does nothing.
Corrective action taken so far :
1. reseated CPU in socket; verified orientation.
2. replaced motherboard with another new identical board
3. replaced power supply with a new unit
4. replaced/reseated power supply cables
5. reseated/swopped memory modules

Question 1: will the mobo generate the POST beep or is a separate chassis speaker needed?
Question 2: can I bypass the chassis power switch and safely short the input pins on the mobo to simulate
the switch input?
Question 3: is there a reliable way to eliminate the Intel CPU as the possible problem? I do not have another
processor and want to make sure it is the problem before making a warranty claim.

I am fairly dejected right now. Hopefully you guys can offer some wisdom on where to look.

Mister Ed

 

[Mister Ed]

Update: Question 1 has been resolved as I found an old chassis speaker to plug into the motherboard.

 

[Jerry James]

Question 1: will the mobo generate the POST beep or is a separate chassis speaker needed?

Update: Question 1 has been resolved as I found an old chassis speaker to plug into the motherboard.

Separate speakers aren't needed for most boards nowadays

Question 2: can I bypass the chassis power switch and safely short the input pins on the mobo to simulate
the switch input?

Definitely.

Question 3: is there a reliable way to eliminate the Intel CPU as the possible problem? I do not have another
processor and want to make sure it is the problem before making a warranty claim.

Symptoms: Turning on power supply (outlet supply voltage verified) and pressing boot button on case does nothing.

Check if your PSU switch on the back of the unit is ON. If it is, could be a faulty case. Try shorting the power pins with a screwdriver.