Hi,

I would advise reseating all the cards, especially the hidden DSP cards.

The unit should have an LPSU, so I doubt that will be causing any issues, but it may be worth checking voltages.

If that doesn't sort it, try removing cards one by one. You'll need the digital input and output cards, the two hidden DSP cards and the CO00 comms card as a minimum.

Let us know how you get on.

Cheers,

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.