pioneer a605r keeps switching off

[homertooties]

Hello eveyone has been a wile since i have been on here,

I am trying to fix a pioneer amplifier,when you switch it on after about 5 seconds it switches off ,the speaker relays and the signal relays chatter like hell for about 4 seconds .
The amp is powered by a little board connected to mains with a timing circuit swithing transformer on.

I thought it was the hexfets took them out,amp still does it (irf540 and irf9540 out put stage.
Took all relays out still doing it ,but if you press the direct button in ,the amp stays on,inputs are controlled by the common tc812cn chip there is another bigger chip behind the input switching..does anyone have any ideas or a schematic of this amp .cheers