Toaster

Here we have a Kitchenaid toaster, model KTT570WH0.

Circuit board normally held in by white vertical slots.

Detail of control board. Really a rather sophisticated toaster, it has warming, defrosting, and bagel modes. Time is controlled by a rotary encoder and displayed on a single seven segment.

The two black wires exiting the lower left of the prior frame go to -- toast compensation! Here we have a little diode or thermistor (it says thermistor, but could be either) used as a temperature sensor.

The toast compensation board's slots key into the tabs seen above and below the hole, and they are then twisted/bent to hold the board in place.

Here we find the problem. I disassemled the relays partially to examine the contacts, and the middle relay had serious arcing issues -- it controls the center element, which explains why the toaster was experiencing the problem that it was (very weak center element). I attempted to clean it with a cocktail of deoxit and scotchbrite to no avail, as the center is simply too pitted.

Another view of the power board.

Central view of the power board. The left two relays control the center toasting element -- whether it is on, and whether it is in series with the outer toasting element for the warming function. The rightmost relay is used to shunt across the diode -- or not -- which engages bagel mode, as it puts only a half-wave through the center element. Featuring another capacitor zener supply, this one's quite hefty to power the relays.

Here we have the solenoid to hold the toaster down.

Detail of power PCB.

Detail of power PCB.