How to troubleshoot the hot air oven that cannot be heated:
The hot air oven cannot be heated. The parts and components that affect the normal heating of the hot air oven mainly include: AC circuits, transformers, relays and electronic tubes. If any of these parts and components fails, the AC circuit of the electric oven will be disconnected, so that it cannot be heated normally. Here's how to troubleshoot.
Plug in the power:
(1) Observe the signal light, if the red light is not on, and after half a minute, the relay does not act, and the tube filament doesn't light up, the AC circuit may not be connected first, and the fuse RD can be checked with an electric pen from the mains line in turn. Whether there is electricity at the terminal points such as the safety controller KK, the power switch K and the transformer primary. If it is normal, it may be that the transformer is damaged, and it can be further checked and replaced with a multimeter.
(2) The red light is on, but the tube filament is not on. This is obviously a damaged tube or a malfunction of the header, and the header 4,5 pins should be carefully checked for good contact and for disconnection. Remove the tube and measure 4,5 pins with a multimeter ohm, if it burns out, replace the tube of the same model.