back light or indicator lights - only one stays on?

[auteurist]

Very strange problem. I was troubleshooting a W500 with an intermittent back light when I realized that the inverter cable was loose.
Tightened it up, back light goes out, all indicator lights go on. Loosen it up a bit, back light goes on, indicator lights go out (except for wifi).

Now this, I cannot explain. I'm almost certain that I've seen this issue passively mentioned on these forums, but have been unable to locate the thread.

Is there anybody who has some explanation behind this?

Thanks!