Science/Engineering/Technical forums

I have a problem with my turbopump controller that seems odd to me, but it may be obvious to those with more electronics experience. It only works immediately after being powered up when it's above 80F or so. It hasn't been a problem through the summer months, but now that it's getting colder I have to hit it with a heat gun for a few seconds to get it to start. In a room temperature environment it'll start after being powered up for 10-15 minutes. So, are there any specific electronic components that are prone to that type of behavior when they're on their way out? My other option is to go component by component and cool them off individually until it quits.

Joe

Check out the startup components for the switchmode device usually several high value resistors in series from the DC bus to the device (these tend to go higher in value causing undervolt lockout). Also replace all small electros around the switchmode device.
Another item that does wear out is the optocouplers, emission from the IR LED goes down with age --get it working and hit these with the cold spray.

Thanks John. I was snooping around the optocouplers the last time that I had it apart, but I ended up putting it back together and using it before I came to any conclusions and I didn't have any cold spray on hand at the time. The resistors didn't even cross my mind, but I have some things to focus on now and maybe narrow the search.