Hi i recently encountered a problem with one of my 6021 controllers where the after a few minutes running the loco lights started to flicker, luckily one came up for sale and so i bought it, unfortunately the problem remained. So i swopped controllers and the lights flickered on the alternative controller. My controllers are connected to plugs and sockets so i can swop to analogue and i discovered that the wires to controller question was to heavy a gauge, substituted thinner cable all good . Hope this might help someone Phil.

Totally agree with kiwiAlan. Problems usually occur when your wire gauge is too small, not the other way around. The act of replacing the wire caused whatever your underlying problem was to be fixed, not the fact that you used a smaller wire gauge.

What power supply are you using? Is it a dedicated transformer for the 6021 (600X) or is it a regular transformer (664X)?
I don't know what kind of issues would cause flickering of lights. You mention that on the first one, it was the lights on the locomotive that were flickering.
You then mention that "the lights flickered on the alternate controller". Did you mean the LED display on the controller or did you mean that the locomotive lights still flickered with the new controller?

The gauge of the wires is not too major, as long as the wires for live and ground are of similar type. Using two different type wires can create a weak spot, especially where the wires are connected to transformer, track or other connection. Most often, this would be noticeable in terms of heat and not in flickering of lights.

Might I inquire as to the model of the locomotive in question? Some older locomotives still had the lights connected via the chassis for return and this caused flickering in digital operation. Newer models had the lights connected by wire directly to the circuit board/decoder which solved the flickering issue. Was it an older 36XX lok (1990s)?

Regards

Mike C

Hi the controller in question was connected to the correct transformer, the locos lights flickered on a range of locos Marklin old & later models fitted with 60760 decoders Fleischman Roco Piko Lilliput locos fitted with Lokpilot or Roco decoders, another 6021 controller connected to an anaologue controller did not suffer with this problem.The wiring was tested with a meter & no issues were found with the connections as i said problem was solved by a cable change. does not really make sense but it worked. Best regards Phil