LED Iight not works even after replace

The wiring for the lights shouldn't be complicated; basically you should have power going to the switch, then the switch powering the LED board. You already know the problem isn't the LED board, which really only leaves the wiring itself or the switch.

Since the switch is a mechanical component subject to wear, that's the place I'd look. From the parts diagram it looks like there's a tab holding the switch in, but I can't tell from the pictures whether you can take it out by itself or if you're going to have to take the whole shelving unit off to get to it.

However you have to do it, you should be able to test it by simply unplugging the two wires, then shorting them together. The light should go on at that point, which would confirm the switch is bad. You could try some electronics cleaning spray on the switch, but if that doesn't help you'd need to replace it.

If you have an ohmmeter you could verify the continuity changes when you operate the switch, and confirm with a voltmeter that the switch has power coming to it. It's a heck of a lot cheaper than the LED board, so it might be worthwhile to just replace it.

Good luck, and let us know what you find.