I tend to look up the manual to see if there is something easily done, go to the manufacturers website or sometimes google.

In the past we blew a heap of money trying to fix a printer. It cost a heap to buy new cartridges (the older they are the more they seem to cost), then to buy in a specialist head cleaner that did not work in the end. When we bought a replacement, we realised that we could have bought 2 for what we spent trying to save the old.

When is comes to white goods, we call MIL's partner, as he repairs them for a living. He gives us an idea of what we can do and if it is worth it. Pity they are in a different state. Next visit we are asking him to bring his toolkit