To remove back of Harmony 650 - 6 screws

The problem with your Logitech Harmony 520 backlight staying on is with the timing crystal.

This is a solid state component that is responsible for telling the remote when the light has been on long enough.
It is very common in these remotes for the timing crystal to fail, thus your glowlight stays on until the batteries are dead.

If your Logitech Harmony is under warranty, contact Logitech Support (1-866-934-5644) to have your remote replaced.

If you are handy with soldering solid state electronics, the part you want to replace looks like a capacitor. You can buy what you need from any electronic parts store or hobby shop, just ask for a 32.768KHz crystal.

I hope that helps.
__________________________________________
Logitech Harmony Firmware Update
Harmony Mac Software Download
Harmony Win Software Download
Harmony Remote Glow Light Fix
Logitech Harmony Safe Mode Fix

The problem with your Logitech Harmony 520 backlight staying on is with the timing crystal.

This is a solid state component that is responsible for telling the remote when the light has been on long enough.
It is very common in these remotes for the timing crystal to fail, thus your glowlight stays on until the batteries are dead.

I am not aware of a way simply disconnect the glow light.

If your Logitech Harmony is under warranty, contact Logitech Support (1-866-934-5644) to have your remote replaced.

If you are handy with soldering solid state electronics, the part you want to replace looks like a capacitor. You can buy what you need from any electronic parts store or hobby shop, just ask for a 32.768KHz crystal.

I hope that helps.
__________________________________________
Logitech Harmony Firmware Update
Harmony Mac Software Download
Harmony Win Software Download
Harmony Remote Glow Light Fix
Logitech Harmony Safe Mode Fix