Many thanks for the quick responses, I'll follow your suggestions and see what happens.
Cheers,
Dave

Son and I very new to model RR, newer Yard Boss 0-6-0 - has been working fine then next day turn it on and won't run or runs intermittently a few inches then stops - can "jiggle" engine and might run a couple of inches then stop, or still not do anything.  Train is hardly used.

Can anyone provide some steps to troubleshoot......or any thoughts on potential problem?  Thanks in advance!