Squeaky - congrats on first flight - now just many more hours to go and the chance to experience first hand the changeable UK weather ;-)
Blinkz - spooky co-incidence on failures. I was all prep'd and ready to go from LBA yesterday on yet another solo CX. A-Check, startup checks, taxy to first hold then expected to do power checks. However the airport was v. busy with GA traffic so it was an expedited backtrack along R27 (across R32), exit then hold. I did so and at the hold I started the power checks. Was then instructed to go on the apron, do a 180 degree turn and hold. I received departure clearance, finalised the power checks and intended to report ready for take off.
It was at this point I did my final round of checks and noticed the HSI hadn't moved! It wasn't aligned with anything remotely like the direction I was in. I checked the compass and of course my heading relative to R27. This thing was not operational at all. Checked the CBs and various switches. Nothing. So had to tell ATC I had a problem and needed to return to the GA apron and flying was cancelled for the rest of the slot :-(
I should have been checking instruments on the taxy, but was busy getting into position. But this was a very valuable lesson in continuing through the checklist line by line to the very end. My method is to talk out loud as if explaining to someone what I'm checking and why. This time I pointed at the HSI and confirmed that it indicated the reality outside. 100% of the time until now it had done, but this one time it didn't.