Yes, the dreaded C
word. It indicates Chinese production but it could equally be used for a four letter word describing these machines.
It could be that the heater relay on the board is failing, moving it may have allowed it to work for a short while. Its worth pinching up all of the connectors just in case.
The small doofer which is hard wired to the board is the NTC or temperature sensor, it should be clipped tight to the inner door panel.
Indesit machines are very prone to oversoaping which is often caused by using combination tablets of any kind. Separate detergent, rinse aid and if required salt is the way to go.
PCB is part number C00252810, yes its the expensive one, just under £50 ex vat list price.
That which can be asserted without evidence, can be dismissed without evidence.