Sir Keks . . . . . . . .
As Davenn said . . . . that FULL WAVE RECTIFIER BLOCK should be bad.
that set of ceramic capacitors are as badly burnt as I have seen.
The way they vaporized I would be wanting to use a much higher rating than 100V . . . . .more likely some X2 or Y2 ceramic units that are voltage rated well-well-well above 100V.
That left corner seems to have a heat shrinked, hidden connector . . . . is that 230 AC in ?
What I am seeing is that you are from Ireland and that would be 230-40 AC power
The center rear board seems to have two pairs of 5 way binding posts on it SPEAKER OUTPUT CONNECTORS ?
Plus it seems like some HUGE power connectors beside them.
Is this possibly a unit that can be both AC line powered or 12 VDC powered.
A cursory look tends to suggest a linear power supply using that toroid . . .but things MIGHT be different, if this unit also works with 12VC in .
What are the voltage spec and capacitance ratings on those centrally located two large, black canned electrolytics.
All that I can see are two POWER semiconductors . . . . . that are using that HUGE heat sink . . . . are any units mounted on its other / unviewable end ?
What is the BRAND and model of this unit . . . . . and it probably will torn out be one that we can find no info on ?
73s de Edd