The power supply you are looking for is a ECM40UT31. They can be sourced from Farnell or RS Components.

Do check Meridian's Technical Note 7a if you have a different PSU installed as the wires need re-arranging.

Just make sure that you tweak the 5v to read between 5.1v and 5.2v for reliable operation.

Good luck.
Steve

Main: 861v6 (LPS), 808v6, UHD722, DSP8000SE Anniversaries, DSP5200.2HC, DSP7200.2, SW1600, Sky Q, Cambridge Audio BD, Roon, M80
Office: 861v4 (LPS), 818v3, 800v4, HD621, M&K S150P, DSP5500HC, M&K MPS2810 sub x2
Son's system: 861v4, HD621, DSP6000.2, DSP5200HC, DSP33
Spare: MCD, 100 Series, 200 Series, 500 Series, F80s, C15s.