'06 250F tach backlight????

Have twin '06 250Fs, and round dash guages. One of the the tachs' backlight is out. Checked all wiring and connections, all seems ok. Are the backlights replaceable if it's a bulb, or is it a bad board/dioide issue....not sure if it's LED? Guage display is fine....just can't illuminate the guage at night. Has 190 hrs. Seems like it's all sealed up pretty well....

thanks...
jim

[boats.net]

Is it Command Link gauge or standard multifunction digital gauge?
No the bulbs are not replaceable.

thanks....going to check all my wiring again.
The tach is a multifunction digital guage...
Is the light an LED? Guess only a reverse polarity, or some internal
fault could cause that to go...esp.since the lights are on a dedicated dash switch, and not used that often.

[boats.net]

Check that the blue wire on speedo is connected to same blue wire as tach is.