My 15 y/o Overhead Door (brand) garage door opener was working fine opening & closing until a few days ago. It has very low usage because I mostly park my car outside the garage door. Now when I press the remote control w/ new battery OR the hard wired wall switch, the light on the opener just blinks on & off about 5 to 6 times and shuts off?. garage door & opener doesn't budge an inch. I tried disconnecting from the safety disconnect chain pull and manually reconnecting but opener still just blinks light. Does anyone have a suggestion on how to trouble shoot before I call the service guys? I think something very minor is interfering with the operation of the garage opener. Any suggestions /tips would be very appreciated. Thanks