Automated Fixtures VL2500 - No Magenta Sensor

[danTt]

Hi Friends,

I have a vl2500 with an intermittent error on the magenta flag, where it likes to home at somewhere on the wheel that isn't open white. I've replaced the color sensor, and the issue still remains. I'm getting a "No magenta sensor" in fixture->status, and I'm not really sure what else to check... I checked continuity on the wire harness magenta wire, and that seems fine, but I don't really know what happens after that wire goes into the main controlboard. Any suggestions?

Thanks!

 

[rochem]

My first thought is that there's dirt buildup on the magenta wheel itself, making it hard for the sensor to find the home position. It's a really common issue with these lights - since the sensor just references a little dab of paint, if there's any sort of crap along the edge of the wheel, it might think it's found a different home position. While you're doing that, be sure to clean and blow out the whole assembly to make sure there's no obstructions or crap inside the light that might be physically impeding the movement of the wheel.

You say it's intermittent - does the unit always/sometimes/never start up correctly (from cold) and find the sensor with no error? If it tends to whack out after a certain period of use, it's possible that there's a heat issue. I've even had issues where putting the head in a particular orientation would cause cables to lose connectivity, but that's generally due to making road repairs with non-standard cables instead of the legit VL parts. It could also be a problem with the motor drifting - less likely, but if you've already swapped out the sensor, motors are cheap and it would be a quick way to cross that off the list.

Do you have another unit that you could swap the entire assembly with? That would quickly tell you if it's an issue within the assembly or whether it's downstream, such as in the cabling or the MCB itself. It isn't unheard of for the MCB to go in this fashion, but hopefully that's not it as that's a very expensive repair.

 

[danTt]

My first thought is that there's dirt buildup on the magenta wheel itself, making it hard for the sensor to find the home position. It's a really common issue with these lights - since the sensor just references a little dab of paint, if there's any sort of crap along the edge of the wheel, it might think it's found a different home position. While you're doing that, be sure to clean and blow out the whole assembly to make sure there's no obstructions or crap inside the light that might be physically impeding the movement of the wheel.

You say it's intermittent - does the unit always/sometimes/never start up correctly (from cold) and find the sensor with no error? If it tends to whack out after a certain period of use, it's possible that there's a heat issue. I've even had issues where putting the head in a particular orientation would cause cables to lose connectivity, but that's generally due to making road repairs with non-standard cables instead of the legit VL parts. It could also be a problem with the motor drifting - less likely, but if you've already swapped out the sensor, motors are cheap and it would be a quick way to cross that off the list.

Do you have another unit that you could swap the entire assembly with? That would quickly tell you if it's an issue within the assembly or whether it's downstream, such as in the cabling or the MCB itself. It isn't unheard of for the MCB to go in this fashion, but hopefully that's not it as that's a very expensive repair.

I'll give the wheels a better cleaning tomorrow, but they've been cleaned out recently and the wheels didn't look terrible today.

As far as intermittent goes, it's intermittent even between recals. If I run an all sequence test it will be stuck in magenta for a while, then be back in white, then back in magenta... it's definately more in magenta than where it's supposed to be, but it doesn't seem tied to heat or similar.

I'll try swapping the assembly as well, that would certainly make things clear--Am I correct in assuming at least that in the wiring harness, the white+magenta wire is the one that runs to the magenta sensor? Or should I be checking continuity on all of the wires in that connector..

 

[soundlight]

I would also try swapping just the little color mixing sensor board if you can. Very easy, it's just a little array of sensors with a harness going to it. It's a known problem that these sensors are exposed to too much heat and can fail because of it, VL actually released an additional part that is a heat shield for the sensors. I should be able to get a picture of the assembly with the heat shield part today if I remember. This failure often starts as intermittent and then becomes continuous.

 

[danTt]

I would also try swapping just the little color mixing sensor board if you can. Very easy, it's just a little array of sensors with a harness going to it. It's a known problem that these sensors are exposed to too much heat and can fail because of it, VL actually released an additional part that is a heat shield for the sensors. I should be able to get a picture of the assembly with the heat shield part today if I remember. This failure often starts as intermittent and then becomes continuous.

That was my first step. I put in a brand new one from VL and it failed the sensor test, which is when I started wondering what else the issue may be. It is annoying though that it fails so easily!