It's a Williams O scale

The E7A works fine backwards but when you change direction to forward there is no movement only a slow clicking sound. It does not sound like gears slipping but might be. Lights and sound all work like they should. This happens whether the non-powered A unit is on the track or not. These were recently purchased on Ebay as new old stock and appear to be new and in original boxes, but the documentation was missing. Don't know if this is related but the new 80 watt power supply died while messing with this, totally dead, light will no come on.
Any ideas about what may be causing this would be appreciated.

The E7A works fine backwards but when you change direction to forward there is no movement only a slow clicking sound. It does not sound like gears slipping but might be. Lights and sound all work like they should. This happens whether the non-powered A unit is on the track or not. These were recently purchased on Ebay as new old stock and appear to be new and in original boxes, but the documentation was missing. Don't know if this is related but the new 80 watt power supply died while messing with this, totally dead, light will no come on.
Any ideas about what may be causing this would be appreciated.