The other day I noticed one of my trackspots not working. I cheked the power supply fuse and, sure enough, it was blown. When I replaced it and plugged the fixture in, the new fuse blew within 2 seconds. Just to be certain I tried it one more time (fuses are cheap), with the same result. I opened the fixture up to see if there were any obvious dead shorts, but everything looked good - no burn marks or bare wire. I don't think the problem is the board, but I could be wrong. The fuse blows so quickly, I think something must be wrong with either the voltage selector or the transformer. The problem is I'm not sure which. The selector looks ok, but I know that doesn't mean much. To visually inspect the transformer I'll have to unwrap it - not something I really want to do. I was wondering if anyone out there knows of an easy way to determine which is my culprit?
[quote=pkingiam]The other day I noticed one of my trackspots not working. I cheked the power supply fuse and, sure enough, it was blown. When I replaced it and plugged the fixture in, the new fuse blew within 2 seconds. Just to be certain I tried it one more time (fuses are cheap), with the same result. I opened the fixture up to see if there were any obvious dead shorts, but everything looked good - no burn marks or bare wire. I don't think the problem is the board, but I could be wrong. The fuse blows so quickly, I think something must be wrong with either the voltage selector or the transformer. The problem is I'm not sure which. The selector looks ok, but I know that doesn't mean much. To visually inspect the transformer I'll have to unwrap it - not something I really want to do. I was wondering if anyone out there knows of an easy way to determine which is my culprit?
I am not familiar with Trackspots, but in other high end stuff (IBeams) of the era, the power board has discrete bridge rectifiers on it, and if one of those goes, it will take fuses just like you describe. It has been my experience that a tranformer is typically the *last* thing to go . . . So, if you can unplug the power board from the transformer and test again, it will tell you if it is the board or not. Rectifiers typically don't give much in the way of visual cues that they have failed . . .
This is caused of 1 of 2 issues. Most common cause is a bad voltage selector. You can replace it or wire around it. If that doesn't fix the problem, you have bad transformer. Those go for about $150 from Lightparts.
Transformer is blown. Replace it and the voltage selector (comes as 1 unit already wired. 4 bolts and your good to go. I do about 15 of these a year on client fixtures.
Yup. Transformer's definitely cooked. When I bypass the fuse and give it power, I can hear it crackle and it stinks of ozone. One more question though: How do I make sure the voltage selector is still good? I assume I can check it's functionality by seeing which lines coming out of it are powered on what settings (e.g. maybe the blue wire carries power on the 120v setting), but I don't know the readings I'm supposed to be getting. I need a standard to check it against. Any help?
Well, that solves that. I really appreciate the help. Still, if anyone out there has the schematics for the voltage selector (or just a way to test whether it's good), I'd love to take a look. If the selector goes bad on another fixture, I'd like to be able to replace it with this one. I don't want to waste my time installing something broken.
PM me if you still want the schematics.. I have a copy. The transformer is the cause though... i've got lots.. same problem. Only had to replace them once though, they've been running trouble free for 12 years!
