Trying to fix my Maplin N78AR soldering station. It’s pretty basic and uses a ‘dimmer’ type circuit to adjust the temperature. I first noticed that the LED power indicator was only on when the temperature was up to maximum, even then it was flickering. After running it on maximum for a few minutes it stopped working altogether.
As can be seen in the photos, the 2 resistors are burnt. The one connected to the caps is measuring about 26 meg ohm out of circuit. The other (R4) measures 1K in circuit.
I appreciate this is a very common and simple circuit, but being a beginner, I need help to identify the resistor value because the colour code bands have burnt away. The triac is a BT136 – 600E and the 2 caps are 2A683J. (They both measure 72nF).
As can be seen in the photos, the 2 resistors are burnt. The one connected to the caps is measuring about 26 meg ohm out of circuit. The other (R4) measures 1K in circuit.
I appreciate this is a very common and simple circuit, but being a beginner, I need help to identify the resistor value because the colour code bands have burnt away. The triac is a BT136 – 600E and the 2 caps are 2A683J. (They both measure 72nF).