OK, starting with the visual inspection again…

• Double check your circuit matches your diagram.
• Is everything pushed in properly?
• Are all polarised components in the right way round?
• Are your stripped wire ends the right length? (5-10mm)
• Have any connections snapped?
• Are the values of your components correct? (resistors, capacitors etc.)
• Is your IC in the right way round?!?

Hmmm… I can’t see any faults. I wonder if this is a red herring, I’ll double check. I’ve checked the position of the base, collector and emmiter using the transistors datasheet found here: NPN datasheet BC109.

I still can’t find anything, all the polarised components are ok, no loose or broken connections, the values are ok… time to power up.

It works! definitely a red herring then.

On to Number 3.