The only panels you will generally have to detach are the side panels like a traditional mid-tower chassis. Both are tool-less and can be pulled off by grabbing the tabs at the rear of each. HYTE does give you instructions on how to remove the front glass panel as well, which includes unscrewing several small screws. We did that, but as HYTE rightfully points out, there is very little rigidity left in that state and you could end up bending the motherboard tray in the process. In the end, unless you are really into a very specific build, the vast majority of scenarios mean you can leave the front glass where it is. The metal side panel with the vent is fully covered in a HYTE branded fine mesh dust filter, just like the top panel.
The interior of the HYTE Y40 is quite similar in design and layout to the Y60, with a few detail tweaks to consider, some design, space and continuous improvements they have made along the way. On the shroud, you will notice that there are now 3 openings, with the one for the PCIe Power cable a bit larger than on the Y60. The two additional ones are necessary as the case height doesn't allow for ones on the motherboard tray. However, the biggest change is the fact that the shroud is now mostly solid, so the floor mounted fan is made essentially obsolete, which is not the right choice for a case that requires the GPU to be upright. Instead of making the step forward to include a 140 unit in the case to improve on what the Y60 offered, you are provided with less airflow in the Y40 with a solid surface area on the shroud.
As the HYTE Y40 does not have a sandwich layout, it has to make due with the constraints of a classic Mid-Tower form factor behind the motherboard tray. As such you get the usual layout, but that doesn't mean that HYTE did not add plenty of unique flair and features to the chassis. Unfortunately, HYTE also did away with grommets on the openings on the side of the motherboard tray. Underneath the shroud, there is a cable duct with HYTE branding that also comes with several hooks for cable ties even though the plastic shroud cover is not meant to be taken off and you will never see that logo in the end either. If you look closely, you can see mounting positions for what appears to be a PCB next to the hard drive tray. This could be a hint of a case with ARGB to come with the same or similar tooling as the Y40.
You will find a weirdly shaped HDD/SSD mounting bracket underneath the CPU cooler cutout plate. This offers room for a single 3.5" drive or two 2.5" units. It is branded and HYTE even went as far as to angle the mounting holes for the 3.5" - just for fun. The mounting frame for the two 120 or 140 mm side intake fans now comes with a few extra structural folds, making it sturdier than the one on the Y60. On top of that the cutouts allow for much more flexibility in terms of the mounting height and also really takes any potential tubing into account far better.
In the front on the bottom, you can see where the I/O wiring comes out that little steel tunnel underneath the shroud. On the floor there is that one 120 mm fan, set to pull air in through the floor of the chassis. As you can see, there is a mounting option for a 140 mm unit, which may have been a better choice, but considering the restrictive shroud, odds are it would not really make a real-world difference in thermals. Above that, you can clearly see the side mounting for the two 120 or 140 mm fans or an AIO of up to 280 mm. The fun fact here is, that thanks to the GPU mounting position, a thick radiator will easily fit as well, without getting in the way of your components.
In the rear, on the bottom, there is the classic PSU bay with two thick foam strips for your power supply to rest on. HYTE mentions a maximum PSU length of up to 224 mm, which should be more than enough for the builds the Y40 is targeting. Above that are the seven horizontal expansion slots alongside the four vertical ones. Just like in the Y60, the Y40 ships with a PCIe 4.0 cable that sports a housing in the same color as the exterior of the chassis - which is red in our case. In the very top, there is that single 120 mm fan set to push hot air out the back of the chassis.
Looking at the ceiling, the 3x120/2x140 mm fan mounting seems less restrictive than the one found on the Y60 and offers a little more flexibility when it comes to fitting your 360 mm AIO as well.
All the wires within the HYTE Y40 are of the usual type, with the added benefit of the USB 3.0 cable being flat. In addition to that, the case wiring comes in one handy, unified connector instead of individual pins. Hopefully, more brands will opt for that in the future.