Applies to: Saffire Pro range
The 'LKD' (or 'Locked') LED on the saffire with illuminate when the Saffire locks to its internal clock, or to an external clock source.
You should test setting the Saffire's clock source to 'Internal' in Saffire Mix Control. If it lights when the clock source is set to internal, it would suggest a problem with your digital connections or the device you're trying to sync to. You should ensure the device you're trying to sync to is set to run at the same sample rate, ensure that the cables are connected correctly (outputs to inputs, inputs to outputs) and whether using different cables improves the situation.