Stoves cooker problems

I have a Stoves EH600 ceramic oven, and the main oven was failing to reach temperature. The switch light was going out after the usual time, so i thou ght it must be the sensor, so i changed the switch and sensor. No problem t here, but.... From that point i had two new problems. The main oven lights are not coming on, i have tested the bulbs and they work fine. The top righ t hob ring isnt heating at all, and the top left hob inner ring isn't heati ng (although its outer ring is). Now my wife did say that on one occasion recently after i removed the oven switch but before replacing it, the top right ring didnt work, and she fidd led with all the switches to everything on and off and it started working a gain. It seems like there's a loose contact somewhere, and maybe the two rings ar e looped together, and the lights share a circuit, or earth point or..... I have looked at all the contacts and they all seem tight. How can i narrow this down? Thanks for any advice, K

In a case like this, where you need an in-depth knowledge of your kind of appliance to diagnose the problem, my best advice is to contact the company that made your stove and find out who does warranty repair work on their appliances in your area. That will be their "local factory authorized repair depot".

I'd contact the factory authorized repair depot and talk to the manager there and see what he thinks could be the problem. That place will sell you parts, and they will make a fat profit off those parts, but the extra you pay buys you the knowledge and experience of an expert in repairing your kind of stove to insure you buy and replace the RIGHT part.

So, when you buy parts from a factory authorized repair depot, you pay more for the parts you need, but you get all the free tech support you need tossed in for free. No one's going to tell you that you get all the free advice tossed in for free cuz these guys are busy and can't spend all day on the phone either, but they know they're making a profit off the parts they sell, and so they'll spend the time with you to help diagnose the problem so that they know what the problem is so that they sell you the right part.