How to Fix PS2 Games Not Launching ("Please Insert Disc") on the ANBERNIC RG556

Causes

Missing PS2 BIOS files — The RG556's PS2 emulator (AetherSX2 / NetherSX2) requires a Sony PS2 BIOS dump (for example scph70012.bin for North America or scph55012.bin for Europe) to boot any game. Anbernic does not ship a BIOS with the console, and the pre-created PS2 folder on the included SD card contains no BIOS folder. Without a BIOS the emulator cannot start the console hardware simulation, so the game loads the disc but immediately falls back to the "Please insert disc" screen instead of booting.
Multi-file or compressed ROM formats the emulator can't read — The stock RG556 setup struggles with PS2 games stored as multi-track .bin/.cue pairs, .mdf images, or ROMs left inside .7z/.zip archives. The PS2 emulator expects a single-file .iso image (or a properly structured .chd). When it can't parse the image, the emulated console behaves exactly like a PS2 with no disc inserted — hence the "please insert disc" error.
The abandoned stock AetherSX2 instead of a patched build — The RG556 ships with AetherSX2, whose original developer stopped updating it in 2022. On the Unisoc T820's Mali-G57 GPU, the stock build has compatibility holes and settings defaults that cause many games to fail at boot. Community-patched builds (NetherSX2) and the newer ARMSX2 fork fix these boot failures, but users who never replace the stock app keep hitting them.
The frontend is pointing at the wrong folder or emulator — When you drop a ROM into the "PS2 folder that was already on the SD card" but the frontend (RGLauncher) or the emulator's own game directory scan is set to a different path, the game appears in the list but the launcher hands the emulator a path it can't open. The emulator starts, finds nothing loadable, and shows the disc-insert screen.
Corrupted or incompatible game dumps — PS2 games are ~1–4 GB and commonly get corrupted by partial SD card transfers, cheap SD cards, or downloads that fail mid-file. A truncated .iso boots to the BIOS/OSDSYS "insert disc" screen even when everything else is configured correctly.

How to Fix

Add PS2 BIOS files to the emulator's BIOS folder — Download a PS2 BIOS pack (files like scph70012.bin, scph55012.bin, scph39001.bin — you legally own these if you own a PS2). Place the .bin files in the emulator's bios directory: in NetherSX2 open Settings → BIOS and note the folder path (typically Android/data/xyz.aethersx2.android/files/bios/), then copy the BIOS files there. Open the game again — if it still shows "insert disc", go to Settings → BIOS and select the correct BIOS region for your game (NTSC-U games need an NTSC-U BIOS).
Convert your ROMs to single-file .iso (or .chd) — Extract any .7z/.zip archives first. If the game is a .bin/.cue set, merge it into one .iso on a PC using a tool like PowerISO or the free bin2iso utility; for .chd conversion use the chdman tool. Copy the resulting single .iso to your PS2 games folder (e.g. /storage/emulated/0/PS2/ or your SD card's PS2 folder). The RG556's T820 reads .iso far more reliably than multi-track images.
Install NetherSX2 or ARMSX2 and remove the stock AetherSX2 — The stock AetherSX2 on the RG556 is the single most common cause of PS2 boot failures. Install the community-patched NetherSX2 (a patched AetherSX2 APK) or the actively developed ARMSX2 fork, which include boot fixes for Mali GPUs. Set it as the PS2 emulator in your frontend: in RGLauncher, long-press the PS2 system and assign the new emulator as the default core. Do not uninstall AetherSX2 until the new app is configured and working.
Point the emulator's game directory at your actual ROM folder — Open NetherSX2, go to Settings → Game List → Game Directories, and add the exact folder where your .iso files live (both internal storage and SD card paths). Tap the refresh icon in the game list and confirm your games appear. Then launch the game directly from the emulator app once — if it boots there, the problem is the frontend, not the ROM; fix the frontend path next (step 5).
Verify the frontend path and emulator assignment in RGLauncher/Daijisho — If games boot inside the emulator but show "insert disc" when launched from the frontend, the launcher is passing a wrong path. In RGLauncher, open the PS2 system settings and check the "Game Path" points to the same folder you added in step 4, and that the PS2 system is set to launch with NetherSX2 (not AetherSX2). In Daijisho, edit the PS2 platform and re-select the emulator and ROM path, then re-scan the library.
Check the emulator's graphics and boot settings — In NetherSX2 set Graphics → Backend to Vulkan (the Mali-G57's OpenGL ES driver is the weak spot for PS2 titles on the RG556) and leave resolution at 1x native until the game boots. In Settings → System, make sure "Fast Boot" is enabled and the correct BIOS is selected. Then in the game's long-press menu, choose Boot ISO (full) instead of quick boot if it still lands on the disc screen.
Re-download or re-transfer the game dump — If a specific title still shows "Please insert disc" after all the steps above, the ROM itself is almost certainly corrupt or a bad rip. Delete it, re-download from a different source, and copy it to the SD card again (ideally via a card reader on a PC rather than MTP, which can silently truncate large files). Verify the file size matches the listed size before transferring. Test the re-copied .iso directly in the emulator.
Test with a known-good game to isolate the issue — Load a small, well-known PS2 title (e.g. a 1–2 GB game) that works for other RG556 owners. If that boots and your other games don't, the issue is per-game dumps or settings. If nothing boots, re-check the BIOS (step 1) and emulator version (step 3) — a missing BIOS is the number-one cause of the "insert disc" screen on a brand-new RG556.