FMCB & FunTuna Setup — Troubleshooting

Companion to the PS2 Modding & Homebrew guide. Covers the boot chain, a clean CNF layout, USB mass: quirks, MagicGate cards, MX4SIO visibility, and a tidy SD layout.

Assumes the SD floor plan from the main guide: one exFAT card with DVD/, CD/, APPS/, and the usual OPL folders. FMCB/FunTuna lives on the memory card in slot 1; MX4SIO (if used) lives in slot 2 for games. USB mass: is the rescue/update stick.

Boot stack: FMCB vs FunTuna vs OpenTuna vs PS2BBL

FMCB and FunTuna are installed from the console itself (wLaunchELF → run the installer ELF with its .7z payload beside it). Keep both installers on your USB rescue stick so you can reinstall without a PC.

Tailored FREEMCB.CNF — mass first for APPS, MC first for BOOT

Why MX4SIO is invisible at boot

An MX4SIO SD card in slot 2 is not visible to FMCB at power-on. The BDM / mx4sio_bd driver only loads after BOOT.ELF (wLaunchELF) starts — typically via the exFAT-aware build that also handles DualShock 3/4. So the live FREEMCB.CNF must live on mc0:/ or mass:/, never on the SD card itself. Menu entries that point at mmc0: / sd: will fail at boot.

Layout that works

• APPS entries (OPL, PS2-Launcher, etc.): mass: first, then mc?:, then hdd0: if you have an internal drive. This lets the SD stay as your game library without duplicating ELFs onto it.
• Rescue entry (wLaunchELF): mc?: first, then mass: — so you always have a file manager even if USB is unplugged.
• No auto-boot by default (LK_Auto_E1 = OSDSYS) — hold a button combo to launch directly if you want it later.
• Keep the editable master FREEMCB.CNF on USB (mass:/FREEMCB.CNF) and a backup on the memory card or SD. Same shape for FUNTUNA.CNF — FunTuna keeps its own config separate from FMCB.

Example

CNF_version = 1
LK_Auto_E1 = OSDSYS                 # no auto-boot; show menu
LK_R1_E1 = mc?:/BOOT/BOOT.ELF        # wLaunchELF — MC first (rescue)
LK_R1_E2 = mass:/BOOT/BOOT.ELF
LK_R1_E3 = mass:/APPS/BOOT.ELF
LK_L1_E1 = mass:/APPS/OPNPS2LD.ELF   # OPL — mass first
LK_L1_E2 = mc?:/APPS/OPNPS2LD.ELF
LK_L1_E3 = hdd0:+OPL:pfs:/APPS/OPNPS2LD.ELF  # future HDD
LK_R2_E1 = mass:/APPS/PS2-Launcher.ELF     # menu only, no auto-boot

# OSDSYS menu items (created by the FMCB/FunTuna Configurator):
# 1: wLaunchELF  → mc?:/BOOT/BOOT.ELF → mass:/BOOT/BOOT.ELF → mass:/APPS/BOOT.ELF
# 2: Open PS2 Loader → mass:/APPS/OPNPS2LD.ELF → mc?:/APPS/OPNPS2LD.ELF → hdd0:+OPL
# 3: PS2-Launcher     → mass:/APPS/PS2-Launcher.ELF
# 98: Free MCBoot Configurator (built-in)

Use the on-console Configurator (or edit the file on a PC) to generate the name_OSDSYS_ITEM_* / path*_OSDSYS_ITEM_* lines — the snippet above shows the fallback order the configurator encodes.

USB mass: hangs, GPT vs MBR, superfloppy, size

What FMCB 1.966 expects

FMCB 1.966 ships USBHDFSD.IRX / USBD.IRX that only handle MBR-partitioned, FAT32 sticks with Default allocation unit and a partition ≤ 32 GB. Anything else can hang the boot — the symptom is a black screen at the FMCB logo with the USB stick inserted, or an empty mass: in wLaunchELF even after hot-plug.

Common failure modes

• GPT partition table (common on modern 32–64 GB sticks formatted by Windows) → hang. Re-partition as MBR.
• FAT32 partition > 32 GB (e.g. a 64 GB stick with one big FAT32 volume) → hang even on MBR. Split it or use a smaller stick.
• Custom cluster size (non-Default allocation unit) → unreliable reads on some drives.
• exFAT stick on stock FMCB → not recognized as mass: at boot.

Fixes that work

• Recommended rescue stick: MBR (msdos) label, single FAT32 primary partition ≤ 32 GB, Default allocation unit. Example on Linux:

  parted /dev/sdX mklabel msdos mkpart primary fat32 1MiB 8192MiB
  mkfs.vfat -F 32 -n PS2RESCUE /dev/sdX1

  An 8 GB partition is the sweet spot — enumerates reliably as mass:.
• Superfloppy (whole-device FAT32 with no partition table, /dev/sdX formatted directly) also works if the device is ≤ 32 GB. A 60 GB superfloppy hangs for the same reason a large partition does. Prefer a partitioned MBR layout unless you have a specific reason for superfloppy.
• Keep the stick lean: one rescue stick holds the installers + a few ELFs. No need for game ISOs on it — those live on the MX4SIO SD or HDD.

Memory card — MagicGate, 256M clones

FMCB only boots from a MagicGate-compatible memory card. Cards that report a MagicGate error at boot are incompatible — typical for cheap high-capacity clones.

The 64–256 MB clones

• Most 64–256 MB cards are bank-switched 8 MB × N with a fabricated filesystem. The PS2 memory-card filesystem (MCFS) runs slower on them, many games only see the first 8 MB, and some titles fail to save (common reports: freezes at boot, fabricated free-space after crossing the real capacity).
• Community reports consistently: cheap 64 MB cards freeze at boot; saves that exceed the real size corrupt silently.

What to use for boot

• Genuine Sony 8 MB MagicGate card, or a known FMCB-preinstalled 8 MB card (e.g. Kaico) — both verified to boot reliably.
• Virtual-card adapters: MemCard Pro2 or SD2PSX — each gives many 8 MB virtual slots; the official FMCB-1966.mc2 image can be written to a slot. These are the safest way to have lots of save space without clones.

Using a large clone anyway

If you keep a 64–256 MB clone, use it only in slot 2 for extra saves. First verify its real capacity: format with Memory Card Annihilator v2.0 (format 8 MiB Full + surface test) and write-verify the full advertised size on a PC if possible.

MX4SIO — why the boot config is not on the SD

The MX4SIO driver (BDM / mx4sio_bd) is loaded by BOOT.ELF after FMCB has already shown its menu. That means the menu cannot reference the SD card directly — fallback paths must be mass:/APPS/… for loaders and mc?:/BOOT/… for rescue. Use the MX4SIO SD as bulk game storage (DVD/, CD/, ART/, etc.) and keep the boot chain on MC or USB.

SD / USB cleanup — what stays where

• On USB mass: and MX4SIO SD APPS/: extract every .7z / .zip and delete the archive — only the .ELF and its support folders stay. Stale archives waste space and confuse wLaunchELF's file list.
• Exception: keep FunTuna.7z beside FunTuna-Fork_Installer.ELF inside INSTALL/FunTuna/ on the rescue stick — the installer reads it from there at runtime. Same for FMCB-1966.7z beside its installer if you keep both.
• On the workspace/PC: keep the original archives in _pc-tools/ (FMCB, FunTuna, POPS, etc.). The card/stick is not the backup — the PC is.

Fresh FunTuna on the one good card — with backup

Do this with a working USB rescue stick that enumerates as mass:. Back up before you overwrite — a full-card PSU backup is ~8 MB and restores the entire card.

1. Back up the current card. Power on with no USB → FMCB menu → plug the rescue stick → launch wLaunchELF (mc0:/BOOT/BOOT.ELF) → FileBrowser → mc0:/ → Mark All → Copy → mass:/BACKUP-MC0-YYYY-MM-DD.psu. Restore later via ULE_psu.ELF if needed.
2. Run the FunTuna installer. In wLaunchELF FileBrowser: mass:/INSTALL/FunTuna/FunTuna-Fork_Installer.ELF (with FunTuna.7z beside it) → Install to mc0: (slot 1) → Normal. Takes ~5 s. Don't power off. To keep the old FMCB untouched, install to a new 8 MB card in slot 2 (mc1:) instead.
3. Reboot and refresh the config. Verify the FunTuna version banner at the top of the menu, then in wLaunchELF copy the tailored configs onto the card:
   • mass:/FUNTUNA.CNF → mc0:/BOOT/FUNTUNA.CNF
   • mass:/SYS-CONF/USBD.IRX + mass:/SYS-CONF/USBHDFSD.IRX → mc0:/SYS-CONF/ (if using the exFAT kit)
   • mass:/BOOT/BOOT.ELF → mc0:/BOOT/BOOT.ELF (the exFAT+MX4SIO-aware build)
   Keep the rescue stick with both INSTALL/FMCB/ and INSTALL/FunTuna/ intact — the MX4SIO SD stays for DVD/ games.