What to do if there is no display on the DynaTrol

How the DynaTrol is Supposed to Work

All of the DynaTrol controlled L&L Kilns have similar control circuits.  Basically, a wire from L1 on the main power block goes to a 1/2 amp fuse, then to a toggle switch, then to the transformer.  Another wire goes from L2 directly to the transformer.  This brings 240 or 208 volts AC to the "line side" of the transformer.

When the transformer is energized by the voltage, it produces about 24 volts AC with a center tap.  This power goes to the DynaTrol on 3 wires.  The two outer ones will give you about 24 volts AC when tested with a multi-meter.  The inner wire gives you about 12 volts AC.  DynaTrol is powered by two 12 volt AC circuits.

What to do if it doesn't work

  1. First, be sure to leave the toggle switch on for 30 seconds without pressing anything.  If the pre-2006 controls are running a program and the toggle switch is turned off without having pressed the STOP key first, the screen will blink, go blank for 10-15 seconds, and come back on when the switch is set back to on .
  2. Check the little control fuse next to the toggle switch.  Push the top of the fuse holder in while you turn it to open it.  You should be able to see the little filament inside.  If it is the fuse, check the circuit carefully for any signs of overheating of shorting, and get a couple extra fuses.  Something caused the fuse to blow and unless you find what it was chances are it will happen again.
  3. If it is not the fuse, you will need a digital multi-meter and be able to work safely around the live electricity.  
  4. With the power to the kiln off, open the control box carefully.  Turn the power back on.  Set the meter to AC volts, the next setting higher than 240 volts AC (on a lot of meters this is 600).  
  5. Locate the transformer.  Most have 3 wires on the bottom of them. The center wire here is actually a jumper wire connecting the two center terminals, and three wires on the top. All wires are on one side of the transformer.  With the meter you should be able to read 240 volts AC on the outer two wires at the bottom of the transformer. (these wires come from the toggle switch and the power block)
  6. If there are 240 volts there, everything is good up to the transformer.  Set the meter to read 24 volts AC and look for this on the outer two wires of the 3 wires at the top of the transformer.  They go to the DynaTrol.
  7. If there is no voltage there, replace the transformer.  If there is proper voltage there, replace the DynaTrol.