Gear Circuit Breaker Popped

[tomcomet]

On today's flight to four airports I had the gear breaker pop twice upon selecting gear down. The gear "looked" to be down but no green light (obviously). Both times I was able to manually reset the gear breaker and cycle the gear UP then DOWN to get a green light and a successful and happy landing.

I have read through some of the older posts here RE gear problems. Tomorrow I will attempt to pump the gear doors open on the ground and have a good look inside to see if I have any frayed wires or dirty switches or contacts etc. Any other ideas??