The Star Trip table has had to wait for a couple of months while I fixed the
self-inflicted problem on the Hot Tip table.
But over the 3 day weekend, I decided to re-tackle it. First I tested it to be sure it still had problems, sure enough turning on the solenoid self-test caused the fuse to blow.
Disconnecting the left drop target allowed everything to run. The transistor associated withthe left drop target solenoid is Q4. So I unsoldered the transistor....again......
and tested it.....another dead transistor!
I soldered on a new one, plugged everything back in...
The fuse blew again.
So I did some cussing, then finally settled down and started trying to figure out what was wrong. I finally came up with what I thought was the problem, the diode on the replacement solenoid was pointed the wrong direction.
There are 3 solenoids, one for each drop target. All use a dual-wire on the left and a single wire on the right:
however, after carefully checking, the diode on the newly replaced solenoid points the opposite direction of the original. Which means either I need to connect the wires on the opposite side or switch the diode to the other direction or the solenoid is going to push in the wrong direction because it is not the right part.
I opted to reverse the wires. Then I unsoldered, tested, verified it was dead, replaced and resoldered the transistor, plugged everything back in...
The fuse blew again.
My wife came out to ask about the cussing. I demonstrated how everything was not working. She suggested checking everything piece by piece and asked about the soldering on the solenoid. I explained how that wasn't the problem and proved it by connecting the multimeter to it...
The multimeter shows that the solenoid is shorted out. So it was time to use my only spare and solder in the new one.
Before I turned it on I finally wished up and decided to replace both the parts at the same time. So the transistor was unsoldered and a new one soldered in. Then I turned it on...
Everything worked!
