MAC 250 Help

[Tofudesperado]

Hello,

I am trying to trouble shoot some Mac 250 kryptons. After giving them a good cleaning I am getting a really annoying error message. They will turn on run through there calibration and give no error. I lamp them on and after a minute or two I loose control of pan and tilt, the shutters close, and a “Hot” error message is displayed. I have tried everything I can think of. I have changed out PCB cards, I have changed temperature sensors, I have checked that the fans are working. From my understanding the “Hot” error shows up when a fixture is turned off and then right back on and is to prevent a hot lamp strike, and is displayed in addition to preventing the lamp to strike. When I get the error the lamp is already on and it stays on. Another use of the “Hot” seems to be when the light sensor does not see enough ambient light. I have tried bending it out a little so it can see better, I have also tried shinning a flash light on it. Both of these have no effect. Of the four fixtures I am working on, two are showing this error in the same way. They do not have the same software version. One is 1.7.0 and one is 1.8.0. would updating them be a possibility? Any help would be great.

-Kevin

 

[Jay Ashworth]

Possible one of the power supplies is going, and when it gets loaded, the voltage dips too far... the controller pulls the load off, and then it promptly retries, and realizes it might be a hot-strike?

 

[bdkdesigns]

My thoughts are on the power supply too. Have you metered the power you are plugging into? Could be voltage drops on that end as well causing the fixture to freak out. When I worked at a theme park, we had that issue where a power conditioner on a roller coaster started to die and we had similar issues every time the coaster would go over the lift hill.

Also, hello, I live near Dadeland Mall currently.

 

[jonslilbro]

I've got one on the bench right now with that exact problem, if I were you I'd try actually replacing the light sensor. Just because you shine a light at it, doesn't mean you can rule it out, if it has a bad solder connection on the small pcb, or if it has completely failed internally, you wouldn't necessarily be able to see it visually, but it would act the same way of letting the lamp strike, closing the shutters and disabling pan and tilt until reset. Swapping the light sensor with a known good sensor would be my first course of action after checking the temp sensors.

 

[jhochb]

Good Morning
What condition is the lamp in? Milky white is a bad thing.
How old is the lamp? Just because it strikes doesnt mean its good.
Check the lamp hours in the INFO menu. Have you ever reset the timers?
Im in Miramar. Call if want. I work on these often & own some myself.

 

[bdkdesigns]

Hello Jack,

Nice to see you on here, I think that you were the one that just handled my portable dimmer pack repair for the University of Miami. I didn't think about the lamp since he seemed to do a pretty thorough inspection as if he knew what he was doing but that could be a part of the problem. I had something similar happen with my Design Spot 250s when I started working here and noticed the lamp issue and haven't had issues since changing it out.

 

[Tofudesperado]

Well, replacing the lamp was of the the first things. I pulled the fixture down out of a night club. Relamped and fully cleaned the fixture. I would not think the lamp itself would be a problem because it is lamping on just fine. I have reset the hours. I will try changing out the light sensor. That does seem to make some sense. I emailed Martin's tech support and they responded by suggesting I change the thermal switch. I don't think this is the problem as my understanding is that the thermal switch does not give any feedback to the PCB. It will, if working properly, just trip and open the lamp circuit once it reaches 165 degrees. Does anyone know if the light sensor is a resistive sensor and can be tested by metering the resistance? Just wondering.

 

[cbrandt]

My memory is a little hazy from the last time I worked on that problem, but if memory serves, it is open (as an air gap) when tripped, and defaults to a closed circuit (zero resistance) when within normal parameters. So if you disconnect the thermal switch, the lamp will not strike.

 

[Tofudesperado]

I think this is right, you can test them with a continuity tester. If there is continuity in there normal state they usually are fine. I pulled one out yesterday that got a little to hot had rather disintegrated. Don't need to pull out the meter when the part just crumbles in your hand.