I've visually checked all the resistors, all the diodes are the correct orientation, all polarised caps are correct. The only thing that I can't check is all the non-polarised caps as I mounted some of them with the legend facing into the back of the panel so can read them in situ. Are any of those critical to the problems I'm seeing?
If there's anything you can suggest Ken it might save me a lot of extra work and a horrible desoldering job.