Does not run and I don't know why

I put the whole thing together being mindful of every instruction.
Connected power, internet cable, HDMI, mouse and keyboard. Time to startup and set up.
I push the power button and… nothing.
I make sure the power cable is firmly seated. Push the power button and…nothing.
I remove the side panel and unplug the start button. I then short together the two prongs on the power switch converter. Nothing.
I take the front panel off so I can stick a screwdriver between things to short the two legs from the switch converter to the Pi 5 board. Nothing.
I am using the big Pi 5 power supply. The Pi ran fine the last time I used it.
Disassembly will happen on another day to investigate further.
Not happy.

Please provide us with a problem video so that we can analyze and solve the issue.
You can upload the recorded video to your OneDrive and then share the video link with us if the video is large.

A problem video? There is no need for a video. All you will see is an assembled unit not doing anything. There will be no LEDs lit up, no fans running, nothing on a monitor.

Disassembled the unit and found that the Pi 5 is dead. It was working before but not now.
I will buy another and attempt to build again. Hopefully I will then have a working assembly.
(Yes, I made sure the power supply is good.)

If you have tried to use the PI5 on its own and it is still unable to start up properly, it’s possible that the PI5 itself may be damaged.
Additionally, please ensure that when assembling the PI5 with the Pironman5 enclosure, you follow the assembly instructions carefully.

I found the cause for the PI 5 to not run. It is the heatsink fan.
I had left the power cable connected and decided to remove the cpu heatsink/fan assembly to get ready for the PI 5 I ordered yesterday.
The PI 5 came to life, the LEDS lite up and started flashing.
It looks like the problem is the fan for the cpu heatsink.
I did make sure that the pins on the PI 5 connection are straight after unplugging the fan. That would have made a short across which ever pins could have touched.
So, the PI 5 runs without the PIRONMAN 5 heatsink fan plugged in and won’t run with it plugged in.
Sounds like I need a new fan. Not the whole heatsink assembly. Just a fan.

Please provide a video of the issue and the heatsink picture.

Video. I am not going to put the CPU cooler back on the PI.

(Attachment PI 5.MOV is missing)

Picture, I had to separate the video and picture due to size constraints in my email client.

I tried sending a video but it was over 9gb. That is about the smallest I can do. Here is a still photo of the pi lit up without the cpu cooler attached.

You can upload the recorded video to OneDrive, then share the video link with us and give us access permissions.
That way, we will be able to view your video.
Also, please share a clear picture of the wiring for the heater fan, so we can analyze whether the fan wiring is reversed, which could be causing a short circuit.

Picture of the wiring and pin side of the plug.

How much $$ is a fan? I will buy a replacement. If it has to be the entire cpu cooler, I will buy that.

If you are sure that the cooling fan is interfering with the normal operation of the Raspberry Pi 5.
It is necessary to replace the cooling fan.
Please contact us at service@sunfounder.com

Are you sending a replacement fan? I have tried contacting via email. My email provider tells me they cannot find service@sunfounder.com.
I have already offered to pay for one if need be.
Please let me know what is going on so I can plan accordingly.