UK Wii Console with Australian Games: Won't Work—Region Lock
Australian Wii games will not work on a UK Wii. The consoles are region-locked to different video standards and region codes.
Why It Fails
Region Locking: UK = PAL (Region 2). Australia = NTSC-U/C (Region 1/4). Wii consoles only play discs matching their region.
Video Standard Mismatch: PAL (50 Hz, 625 lines) vs. NTSC (60 Hz, 525 lines). Even if region-free, the signal mismatch causes rolling, b&w, or no picture on many displays.
Solutions
Buy a PAL Wii (UK/EU) for UK/EU games.
Buy an NTSC-U/C Wii (US/AU) for Australian/US games.
Region-free games are extremely rare on Wii (mostly homebrew). Always verify region before buying.