I referenced the oven repair in the following post on T4 HDMI issues:
viewtopic.php?f=50&t=14834
I'm sure anyone will understand that the T4 issues trump repair of any food preparation device as experts have stated it is possible to survive three days without water and three weeks without food, but during an extended lockdown I'm not sure it is wise to go any length of time without adequate functional entertainment resources....
The problem state was that when power was applied, the igniter would spark for about 15-20 secs and oven light (neon) would come on despite the oven not being switched on. When the oven was turned on, there was no way to light it - the igniter powering at switch on, without detecting any flame/heat, had locked out the gas solenoid. This was apparently due to power going to that neon (and associated circuitry) that shouldn't be there.
I decided I had nothing to lose by attacking the repair myself as if the oven couldn't be fixed we would need to replace it with a new one, which we didn't want as gas ovens are getting rarer and none are being made with a separate gas grill any more..... so it was worth it to at least mount an exploratory expedition.
I managed to extract it from the wall enough to access the wiring without needing to disconnect the gas or support it underneath. Bearing in mind this unit is 30 years old, the surfaces normally inside the brick wall cavity reflect that age, with an assortment of evidence of past insect habitation and the accompanying detritus. You know what I mean. I had to have a vacuum cleaner at the ready to give each part a thorough going over prior to removal.
Thankfully there was also a circuit diagram on the side of the oven with all the model info - without this there wouldn't have been much hope as there is no information available anywhere for such an old unit.
In order to examine the wiring I also had to disassemble quite a bit of the oven to get the front glass panel off to access all the connectors for the switches, knobs, etc., laying everything removed out on the floor so I could return the right fitting to the right place. Having done this I was able to measure ~400 Ohms between the active of the neon and the active on the other side of the Oven switch, which in theory should have been much higher - so power was getting there somehow. The layout wasn't a direct translation of the diagram so there was interpretation needed to work out what wire did what or went where..... I also noted some tiny "chips" and chunks missing from the insulation on some of the wiring - these all appeared to have some high temp silicon blend of insulation, not the normal rubber which may not have fared as well over its lifetime. No conductors were exposed and the damaged bits weren't in locations where there was a possibility of shorting against anything but I did silicon wrap wires in a few spots just to be on the safe side (none of these were high voltage - just the 240V running between components).
I tested all the switches, disconnecting connectors to isolate and trace where the rogue 400 ohm resistance was coming from. I had to be gentle as quite a few of the plastic components were a bit more fragile than usual due to ageing in a naturally hot environment. After a lot of careful prodding and poking I noted the resistance between the neon and other active supply had risen to around 400 K ohms - I had to double check as I wondered whether I had just not noted the range indicator before, so I carefully replaced the wires, propped the front panel making sure there were no shorts and powered up the oven, lo and behold it was now working properly again!! .....so something I had done had dislodged or removed whatever was causing the low resistance and allowed the oven to behave normally.... there was quite a bit of dust built up around some connections although all the crimp connectors were in plastic housings and close fitting on the terminals so there didn't appear to be much room for anything to collect that would result in that low a resistance... Anyway, after a clean of the front panel I buttoned it all back together and re-installed it in the brick cavity and it's been working well so far. Overall it took up an entire afternoon but I feel a lot better about not having to replace it or get a service tech in to charge me much more to achieve the same result.
