It's time to mount the PSU and install the mainboard on its plate. One problem occurred, though:

As you can see, it is hard to use a graphics card with a reverse-side heatsink in this barebone. Particularly, it is impossible to put the mainboard plate in its place when such a graphics card is installed. As a result, I replaced the graphics card with a less advanced model that had a normally located cooling heatsink.

Besides being compatible with our barebone, this cooling system has one more advantage: the PCI card can be installed right next to the graphics card without worsening the latter's thermal conditions.

The manufacturer recommends installing the PSU with its intake fan facing upwards:

This is a proper solution: the CPU cooler shouldn't be deprived of its air. Just as I had anticipated, there was more than enough room between the PSU and the CPU cooler for the latter to work normally:

The optical drive cage goes into its place. The cables get attached, and the system is almost assembled:

Just put the cover back and appreciate the result:

This looks fine, although it is going to take some time and effort to normally lay out all the cables in this barebone. There's too much of excess cabling in there. The front part of the case is highlighted with a mild blue light from the fan:

This looks nice and is not irritating at all because the light is not intensive.

So, the system is assembled and can now be tested. Here is a brief specification of the system case.