Red LCD light on I/O Board

[roskruge]

Mac Pro 6.1 (2013) A1481 - OS10.14.6
Computer it’s not starting up but that is not my main concern. I have always until now always powered up with the outer shell on. So I did not see the I/O board has a red LCD light, red light tells me Power is Getting from the power supply to the I/O board. But it is not getting to the front panel white indicator lights, even when the Outer shell cover is on. Even though power is getting to the I/O board there could be a faulty Connection power supply to I/O board.
What is the relevance of The red light. Also if everything Is working OK would I get a different color light ?.
This is one for the Mac professionals
Thank you as always

 

[roskruge]

Looking at the I/O board when not attached to the computer even with a magnifying glass it is not possible to locate the source of The red light. Red Light Is very bright and is on continuously when computer is plugged into power even when computer itself is not on.
Location - looking at the above two photos it is in the bottom left-hand corner of the lower photo just to the right of the screw connection. Between reset button and screw connection.