Wharfedale Titan 12 Active - no Output, Low Rail voltage

[MojoAmpGuy]

I am struggling to diagnose a Titan 12 Active speaker issue. Unit powers up. yet no output signals.

Power supplies

+15 v = +15v
-15 v = -15v
+35v = +35v
-35v = -35v
However
+70v = 58v
-70v = -58v

Does anyone know why the +/- 70v rails are measuring low?

P.S other key measurements

Mute measures -15v
Protect to negative rail measures 0v.

output FET’s appear OK

Running out of ideas. Any suggestions welcome. Thanks

[The Dude]

A schematic would help.

[diydidi]

Have you checked the two large capacitors used for the ±70V rails? They might measure high ESR.

[Jazz P Bass]

Here is what I have for the Titan 12.
There are different versions.