Its brand new first timr it has been switched on
the top oven works ok - the propblem is the main oven/the bottom oven
when you turn the bottom oven on a himming/viberating noise starts and slowly builds up to a load noise as the oven warms up.
if you turn the oven dial to off the noise stops - turn it back on and the noise starts again - turn it off the noise stops.
I'll come back to you tomorrow, after I check the back cover screws
if thats ok