I know that on the ESU line of decoders the LED brightness can be adjusted from a setting of 31 down to where ever I like it in the decoder settings. I have a ZIMO 621 that I am using and have not found any way to adjust brightness down in the decoder settings. I have resistor on the LED but still too bright. I am using JMRI. I have attempted to find the info in ZIMO manual, no luck. Maybe they don't have that feature? ? ? Any thoughts appreciated ! !