If you have checked the power supply and thats fine then you need to check the main control board at the back at the bottom.
Remove the back panel and there in the back left corner you will see the main control board.
Remove this and open the plastic casing and remove the control board from the holder and see if theres any signs or burning on there.
Also see if theres a slug in there. Sounds crazy but its something we are finding a lot on these. Slugs crawel into the board and short it out and blows the board and this causes it to loose power.
So if this is the case you will see it so the board will need to be replaced and programmed up. But i have also seen this take the front board out as well but you wont know untill the main board has been replaced.
But the cheaper option for this is to get Indesit in to fix this as they do a fixed price repair for £110 all in so for that price they will call out and replace the control board and program it up with there laptop. Then if it needs a front board this can be fitted as well.
So check the control board and see what you find. But as to the fault were theres no power and the supply feed is ok then its nearly always the control board at fault here.
If you need anymore info just get back to me.