In-laws had their kitchen done a year or so ago so gave us their perfectly-working but dated (15 years+) Bosch dishwasher which has been sat in our garage unused since. Recently connected it up in our kitchen but no water getting in (yes it’s all connected up properly) – not sure if the pump’s pooped or something is blocked. We think the pump might have gunked up without regular use (the garage gets damp during the winter).
If there are any dishwater experts here, do you think it’s worth getting someone to look at it or is it probably ‘non-financially viable’ to fix? I guess if it costs eg £100 to fix then a new £200 one is a more sensible option.

Use a google search. Common faults are impellor jug motor thingy and another wotsit, both easily sourced online. If water has leaked into the drip tray at the bottom, a float switch will shut it down, simply tip the machine over to drain any lost water and off you go again.