De Dietrich Double Oven Control PCB Replacement

Введение

How to repair a broken light problem, having tried a new bulb, and no display or working oven.

Repair an electric Double Oven. (UK and 240vac mains current)

Repair a broken light and no lower oven working. No display or function buttons.

You will be working on live and exposed wiring components. Disconnect and switch off from wall outlet. No Internal light working and lower oven function or display. Note that this oven has two similar control pcb's. You can compare one board to the other.
The lamp has been replaced but still not working. The next thing to do is check out the lamp wire end connections, the terminals went high resistance on my unit, replacing the push on connectors was easy. The connectors are the type used on cars and I had some handy. Re-testing still no light.
Tracing the lead wires back to the control pcb I noticed the small relay looked bad and this only applied a neutral return.
Pulling the relay showed more blackened marks. So the relay was replaced. Success now the light was on again.
Moving on to the lower oven with no display or function buttons working. Checking the output from the small 12v 5VA transformer was zero. 240V AC input was there. A slight bulge on the top of the transformer confirmed a problem, it was also coming out. Resistance on the primary showed o/c windings.
A new replacement from Farnnell was fitted. Part number 1689081, (Manufacturer part number 44231)
Testing and the controls were restored to normal.
The new transformer was made by Myrra (not Tamura as in the photo) and that a Myrra unit was working on the other controller pcb. Guess the factory used both.