Hi Christopher,

If the blue LED is not lit, you don't have -12v from the PSU. If you have a meter, you can measure the output voltages of the PSU with it disconnected from the PSU board - Black is common, Red is +5v, Yellow is +12v, and Blie -12v.

It is most likely that there is a fault with the power board. You can confirm this by removing the CO00 card (carefully as it has a ribbon cable to the front display), if you pull it out a centimeter you shouldn't need to disconnect the connector. If the blue LED then lights, the fault is on the CO00 card.

If you need to completely remove the CO00 card, make a note of the orientation of the display connector - if this is wrongly connected, you'll blow the display and the CPU card!

Let us know how you get on. If you need any parts, please drop me a PM.

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.