When a constant combinator is set to only output negative values the light will not turn on even when the combinator is on.
All four combinators are turned on, however the top two have their lights off because they are only outputting negative values.
[0.14.21] Constant Combinator sending negative signals don't show status light
Re: [0.14.21] Constant Combinator sending negative signals don't show status light
Fixed for 0.15.
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