Remove both side panel access doors. Remove your top black acrylic skinny finish trim panels from both sides of case so you can gain access to the fins, their hinges and their screws. When you power up, look to see what is making your 2 fins stick. If you have to, "help" them unstick. Then open Command Center, active venting, have CC open the fins and shut them a couple times. Do this to test for sticking. It usually comes down to the torque of the fin screw, or the torque of the trim panel screw. Unless of course you can see what is causing it to bind, like an obstruction.

You can try to back off the torque a little on the fin screws on the 2 fins that are sticking. Reseat their screws to a suitable torque if-when they revert back to normal. Retest w/Command Center, open/shut. If all is well, reinsert the finish trim panels, and reseat their screws, but not too tight just yet. Retest with command center to open shut fins. Usually, the finish trim screw closest to whatever fin is sticking is the culprit, so tighten or loosen it based on whether any of these tips have helped. As long as the finish trim screw is almost tight, it will keep the trim on, and not make the fin stick ...

Basically, remove your case doors, remove the top trims, power up, and go from there ...

To tell if you have an ALX with a motorized front panel, look at your exterior case panels, the "paint job";. is it "shiny" or "flat"? ALX has a soft matte black finish, barely any shine; standard Area51's have semi-gloss rather shiny panels. Open your side panel doors. Look at them. Standard A51 doors have full aluminum inner plates. ALX has a full black. This is true for both sides. Compare yours to the pics. If you have aluminum inners, your front panel has no motor, your alienhead does not work, it is not an ALX. If your doors are black inside, your alienhead should open/shut the front panel. If it doesn't, there are threads to search here in the forum to help get it working again.

Need further proof? Take your door off, use a flashlight, look at your daughterboard to the right of your power supply, in the bottom right of the case floor. An ALX daughterboard has a white door motor connection (see pic), and obviously needs the door motor connector inserted in order to work. A standard Area51 has a daughterboard without this connector; it has no motor, so it needs no connection for one. The daughterboards are different; ALX needs the connection, non ALX does not need one. If you have a shiny paint job, with aluminum inners, an alienhead that doesn't work, & your daughterboard is missing that particular connector, you have the base Area-51 model ... Got it?

Look for the ALX motor connector, circled

Non-Alx daughterboards do not have the white motor connector; it is missing, like photo below

matte / satiny ALX

shiny / semi-gloss non-ALX 'standard' Area-51