The Pandora’s box uses a TF/ micro SD card located within the console casing.
This card has a number of partitions and in most cases stores the encrypted games. Depending on your Pandora version it may include the operating system as well.
If your console is experiencing issues loading up or doesn’t show games, it may be that your card needs to be re-seated or replaced, here is a quick guide;
Prior to commencing ensure all cables including power and HDMI have been disconnected from the device and that your hands are clean, dry and moisture free.
With the dual split case consoles the player one unit shown below houses the main motherboard and TF/ micro SD card.

The case can be opened by flipping it upside down to expose the screws located towards the lower front. Keep in mind how and where the joystick(s) sit and lean when the unit is upside down so as to not damage them. Remove the screws at the front using a Phillips head screwdriver and place them somewhere safe. Depending on your deck type and size the top might be screwed in or mounted slightly differently.
Before opening the case, while the chances are minimal, try to not touch the actual board itself as you want to avoid static electricity from your body causing any damage.
While you can search the web, put simply you can remove built-up static from your body by touching steel and reduce build-up by not rubbing/dragging your feet on the carpet.
Depending on your model the slot can be located on different parts of the board.

For example, while most micro SD cards sit front left, the EX board has it located on the right side towards the back. It uses a push mechanism without any glue.
The case has a slight indent around the slot, that can make it challenging to reach, thankfully a small push should have it come out enough to push back in and reseat. Some tape or a small amount of Blu-Tack might help it out a little once pressed in.

While the top of the case can’t be removed as it has two screws holding it in from underneath, this picture shows the card once pressed in and released. Be cautious to not pull it right out as can be challenging getting it back in due to the clearance and access angle of the slot in your machine.

Back to the types of card slots being hinge or push. The push type usually has a dob of glue, which you can use your fingernail to pick off slowly. Do not use steel utensils that could slip and damage the device. Gentle and slow is the key here.

The hinge card slot has tape placed over it, which can be peeled off. With the adhesive removed, the slot tray can be held with your finger and slid backward.
It can then be lifted as it is rear-hinged and the micro SD card lifted out.

With the push type, once the glue has become loose and removed from the metal surface by using your fingernail, it will easily come off from the card as well.

You can then push the card inwards which will activate the quick release freeing it to be easily yet carefully pulled out. Keep in mind the card’s contact points underneath as you want to avoid scratching/ damaging the card during removal/insertion.

Once removed the card’s contact points can be wiped on your pants, top, or rag and then re-inserted/ seated, console closed and powered up again.

If for some reason this doesn’t fix your problem, you will need to either burn a new image onto the same card or source a replacement card with the image/software for your specific model Pandora’s box pre-installed.
Be sure to double-check your micro SD card size as it could be 32GB or 64GB.