The control buttons seem to work and there is a very faint glow on the neon display that is just about visible. The alarm beep is very weak. Do I need a new PCB?
SOURCE: Stoves 720ef electric double oven not working
According to the circuit diagram on page 31 of the handbook, power for the ovens passes through the clock. The power feed is direct for the actual clock but via a seperate Thermal Cutout for both the top and bottom ovens. I think it is highly unlikely that both Thermal Cutouts have failed at the same time. I would try turning the power off totally to the oven for a while and then turning it back on, set the time and ensure the oven is in manual mode. As the top and bottom ovens have seperate controls after the Programmer and both are not working, it has to be the programmer that is not extending the power through to the rest of the oven.
SOURCE: Stoves 720EF oven controller/timer stopped
I haven't tried this myself but if you know what you are doing, then it is worth having a go! Firstly, if you need a new clock/timer for the 720, they are about £80 from espares.
Someone else has stated that a number of oven timers have an electrolytic capacitor which ages and cause the display to fail.. The following is from his post:-
The display went blank, and the oven would no longer operate.
By looking at the specification sheet for the timer, it appears the models vary chiefly on the series resistors installed in the mains supply. On the New World, the mains power goes through a 5.6K resistor both on the live and Neutral, making a total mains series resistance of 11.2K. Newer models presumably consume less power so need different series resistors.
Anyway, I managed to fix my timer. There was a relay, three resistors, a zero-ohm link, an ASIC (Application-specific integrated circuit) chip and an electrolytic capacitor.
Electrolytic capacitors tend to 'dry' over time. In other words, they wear out. The relay is usually in one state and not subject to wear. The resistors checked out OK with an ohmmeter. ASIC semiconductor chips tend to be very reliable. They only fail in times of surge etc, and the mains series resistors would definitely prevent that! This left prime suspect #1. The electrolytic capacitor.
The capacitor on the board was a 220uF 25V radial 125 centigrade electrolytic. These are extremely common components. Any radial electrolytic of 220uF and equal or greater than 25v, and with adequate temperature endurance will do.
I couldn't find anything over 85 centigrade endurance in my electronics box. Bearing in mind my cooker has a cooling fan, and the panel never feels hot, I took the chance on my 85 centigrade capacitor. Rated 220uF 63v.
De-soldered the original capacitor, and making sure I have the polarity correct, soldered the new one in. Polished the display, and all working like new!
As I said I haven't checked this and I presume you would get a replacement from Maplin. The standard radials are part no VH41R and VH43W and the higher heat DT64U. If you did do this you will obviously need to check if this fix is applicable ( is the capacitor accessable) and also the rating of the capacitor. Let us know how you get on.
171 views
Usually answered in minutes!
×