Hotpoint electric oven and grill cutting out

[specialbeat]

Hi, I have a Hotpoint electric oven and grill and the unit has been cutting out after 5 or so minutes. Cut to the chase.
I have replaced the thermostat and still happening. I have on order a new oven element but have now realised that the unit is cutting out when using the grill as well. So I fear that changing the oven element will do nothing to solve my problem here. Is there another thermostat in the unit that's at fault here? Is it time for a new oven? It is about 20 years old and had replaced elements previously. Thanks.
Hotpoint BS53x

 

[Diver Fred]

Separate or a common switch/control?

 

[jj4091]

What do you mean by cutting out, is it just loosing power or tripping a circuit breaker. If it's the former then check the isolator for a loose connection as a first step

 

[specialbeat]

Hi. What I mean by cutting out is all power seems to be temporarily shut off, no fuses are being tripped. Everything shuts off even the clock display.

Separate or common switch control, not sure.
There are two knobs. Left is the oven on with temperature/ or grill on. The right knob is a min/med/full which is always on full.

 

[specialbeat]

The top switch (thermostat) is what I have replaced.

 

[jj4091]

As I said first step is to check isolator for loose or burnt contacts. If that is OK do you get 230/240v at whatever point the cable terminates inside the oven when it goes off