Ha! Do you think that this is caused by failure to shield the blinking IC die from light or is it that the LED is acting as a photodiode and their circuit isn't expecting that? I have noticed before that neon lamps which are beginning to fail (flickering) become sensitive to external bright light. Shining a bright light on them will often make them stop flickering and stay on solid - I think the light helps to make them ionize at a lower voltage. On Mon, Dec 4, 2017 at 3:20 PM, Bob Blick wrote: > Try shining a strong light into a self-blinking LED - I have some RGB one= s > that freeze up if you do that. > > Bob > --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .