Why do my dashboard electronics fail to 'light up' on 5 out of 6 starts.

Hello, please do not waste any time reaching out to your Lexus dealership for assistance. This should still be covered underneath your factory warranty, unless you are beyond the warranty period (which I believe is 50,000 miles). A fuse will never cause "intermittent" failures. If a fuse is blown, it's blown, and will not work at all ever. Your concern sounds like an internal concern with the unit itself which could be software or hardware related.