LEDs & Power
About & Help

NULL Mode Problem

A lot of people have been contacting me all with the same problem. The symptoms are:

  • You plug in the TC420 via USB
  • You upload the mode(s) and test the mode(s) with the play button in the PLed software and it works fine
  • You disconnect the USB but the mode(S) does not run, no lights come on
  • If you switch the power off then on, the mode(s) disappear and NULL is displayed on the screen

Fix Options

There are 2 options for you if you have this problem. The first option is to return the TC420 to your supplier as faulty and hope your replacement is a working version.

The second option is to update the device yourself. You can contact the manufacturer and they will sell you a device to update the processor in your TC420, however these may be sold out temporarily. From discussions I've had with people, the issue seems that there was an issue when the device was programmed. It was initially thought to just be the firmware, but this is not the case.

Please find all the details on this page.

NOTE: Please do not update your firmware unless your TC420 has the error above.

Bugs and Problems

In this page I'm going to try and list all the bugs and problems that are discovered with the TC420 and PLED software, and list any workarounds found for them. If you find a bug that's not listed, send me a message and we can try to find a solution and let others know too.

Saving Packages or Exporting Modes


When I try saving, I get a Visual C error.


Check the name of your package or mode. PLED uses the name of the mode or package as the file name, so they cannot contain any forbidden characters. PLED does not check for this, so you have to be mindful not to use any of these characters in your package or mode names: \ / : * ? " < > |

Crossing Midnight


I have discovered a bug with the controller that seems to effect modes that are transitioning over midnight, in that they don't fade smoothly over midnight. It may even cause random, flickering issues to occur.


The best fix I have found to minimise the problem is to add steps at 23:59 and 0:00 and manually add the fade levels to these times using the tool found here. Just use 23:59 and 00:00 in Channel B's position.