Lamp won't come on Coemar 575MB

[OTO1702]

Hi all

I have 4 coemar 575MB, one of them show an Error : LAER wich means Lamp error. I have change the lamp for a new one. MSR575/2 but the lamp still don't come on.

The pan and the tilt works fine, when we force the lamp to go on, nothing happen. Is there something I have to do ? Even with the controller, we can't put the ligth on but the rest works ok ( pan, tilt ...)

Thanks for your help !

OTO

 

[sk8rsdad]

I don't know the Coemar product but the usual reasons, assuming the unit was previously working, are:

1) undervoltaging the unit. The power supply may be set/jumpered for 220V operation and you're feeding it 120V.

2) The starter has packed it in, or the overtemperature thermostat, or possibly the ballast, but the most likely culprit is the starter.

Once you've ruled out undervoltage, blown fuses, or bad connections, swapping parts with a known good unit can help you isolate the problem.

Hope it helps.

 

[OTO1702]

Thank you !

I will try and get back !

The unit is working at 120V, nothing has changed from the time the lamp was on to the day I have changed the lamp.

I did not opened, maybe some fuse is blown or else !

Thank you,

OTO

 

[OTO1702]

Hi Again,

So I tried and verified all of this :

1. The lamp stopped, no more intensity but the tilt and the pan responds perfectly as usual.
2. I have changed the lamp for a new one. The old one have been used 880hr. But I changed it for a new lamp anyway.
3. The lamp still do not come on even when you force it or you use the test sequence.
4. I have verified the lamp in the other one and it works fine.
5. I have tested the fuses and they are ok. ( I am using 15A fuses for 120V)
6. I have open the base and verified the transformer taps and they are ok.

7. I noticed that the fans do not work at all. These should always be ON as set and they do not work.
8. There is no 12vdc on them.

What could be the problem, the switching unit ? doe's it brake that easily,

Now I am very confused !

Thanks,

OtO

 

[Sony]

Sounds to me like it's a problem with the Power Supply/Ballast, you may have only blown part of the PSU. That seems to be the most likely culprit though, especially if you're not getting any 12vDC to any of the fans. However, are you sure the fans are always on? Sometimes they don't turn on until the lamp powers up or reaches a certain temperature.

 

[OTO1702]

Well I forced them to go on and I still get nothing from them.


For the ballast, doe's it brake that easily ? How can I test it ?

Doe's someone got any similar issues with the coemar's fixtures

Thanks,

OtO

 

[Esoteric]

Yup, you have a power supply/transformer issue. Make sure you are getting something out of your transformer. Also make sure your power supply is good. That is really the only way to verify it. Stick a meter on it (make sure you have it on the appropriate setting!).

Mike

 

[OTO1702]

Ok ! Thanks,

in the case of a transformer (Ballast) broken, Where can I get a new one or old one or a copy ...

Thanks,

OTO

 

[Esoteric]

Where are you located?

Mike

 

[OTO1702]

Hi

In Montréal, Qc Canada ! There is not a lot of Coemar Fans here. People prefer Martin and VL MH.

O.

 

[Esoteric]

I am a HES/VL man myself, but I went to University in Austin, TX about 15 miles from HES HQ. But a lot of rental guys down here have Coemar gear (I am trying to get them turned on to Robe).

Drop me a PM.

Mike

 

[RichMoore]

I know is some power supply units, such as computer stacks, there is an internal fuse, but you have to open up the unit to get to it and most likely, that will void your warranty. Is your unit still under warranty? If not then can give that a shot.

 

[Esoteric]

I have never seen a moving light PS with an internal fuse.

Mike

 

[OTO1702]

The PSU doe's not have any internal fuses. I just do not understand how its possible to blow the ballast. These are Magnetic ballast - Heavy duty transformers. If there is a reason, I should track it, if its heat or undervoltage or surge issues ...

I will start by replacing the power supply from a functionning unit and try ... After that the ballast ...

OTO

 

[Esoteric]

Usually you see a transformer blow from voltage issues or from a short (just saw that on a Martin MAC).

You should certainly track the power as it comes into the unit and see where it is getting thrown off. Heat issues can be a little harder to trace.

Also, they do just fail sometimes. But I would certainly check out your power.

What made me think Transformer/Ballast (especially transformer) is the fans not working when they are set to always on. That tells me that your unit is getting the 120V, but that there is something in the line between the incoming voltage and the fans/lamp.

What puzzles me though is that if your low voltage supply is the problem, then your motors shouldn't work either (unless their power is routed differently). Also the lamp is usually fed 120V and doesn't go through the low voltage transformer. You may have multiple failures there.

I would trace power as it comes in and see where you lose it. But if all your fuses are good it has to be at a distribution point (like a transfomer, ballast, etc). So I think you might have a ballast failure (the lamp not striking) and either a setting issue (you seem pretty convinced you have the fans on though) or a trasnformer issue (but you should be having a problem with your motors or the unit should shut itself off).

Mike

 

[TimMiller]

I havent messed with the coemar 575's in quite a while, but are familiar with their 1200w stuff. Going by memory, if you have the magnetic ballast, you still have a powersupply that feeds the electronics. I would check all of the barrier strips, i have found weird issues caused by the screws comming loose. Does the lamp even sound like it wants to strike? The ballast controls the lamp, not the fans, there is transformer or powersupply of some sort that takes care of that. The 12V that controls the fan's may also be used to trigger a 12V relay to kick on the lamp. Test the lamp safety switch to make sure you are getting contact with the lamp cover closed, if the switch is open the fixture will be dead or at least not strike. Take a few pics and post them, and i can help you out further.

 

[OTO1702]

These are very helpful info's

To respond to some questions asked ...

The motors works perfectly, controlled via Sunlite, the yoke can pan/tilt, open the iris, shutter ...

The main transformer is an autotransformer ( 230V/120 : 14-14/12-12), I can read the wrigth voltage coming from the secondary of the transformer. So the 14V and 12V are ok.

The fans are fed by a little power supply using some basic electronic parts, his output should give me 12vdc and 5vdc, the meter show's 0V. That's why I suspected the PS.

How can I test the ballast ? is there a safe way to see what goe's out of it with a simple fluke ?

Is there some relation between fans and lamp ? who starts first ?

I will take some picture on Monday and send you gice some test points !

By the way, I find these lamps fantastic and easy and cheaper (used stuff) and very well made, pretty easy to work with !

Thanks again,

Ot

 

[OTO1702]

Hello All,

Just to let you know for your information what was all the issue about,

Because of the fan not working, the problem was more into the control than the power. So all the ballast/transformer issues were out of suspicion.

In all that kind of lamps, we have some solid state relays or triacs or else. Thes are used to switch the lamp fast. This relay have to be energized by the control board. So, the first step was to test the lamp to see if it arc, the way to do it is by jumping the Solid state relay. By bypassing the SSR, the lamp came on and worked properly.

At this point, I suspected the control supply board. This board will switch on the lamp only if there is some 12vdc going trough the fans switch, its like a heat protection. The lamps can go up to 300 degrees C which is pretty hot!!

After disconnecting the board ( see picture). We traced the signal up to the output. I had about 37V in but 0V out. The problem was around the smoothing choke coil which was not soldered anymore. I guess, vibration has created the issue !

So that it, problem solved ! Thanks every one for your Help !

Othmane

 

[JD]

That was a good share! Chances are many of those units will developed the same problem. Over the course of my life, I have serviced over 20,000 units in all fields. There are several "truisms" about road equipment. 1) If its big and heavy, it will unsolder itself. (why the lord invented GE silicon.) 2) If the leads are thick, they will develop ring cracks.

There is a third truism that needs to be spoken about: "Don't die fixing your equipment!" The ignition circuit for HMI lamps generates in excess of 20,000 volts which will stop your heart. :shock: Although I am glad you had a happy ending, it is important for others to note that we never recommend attempting service on electrical equipment. Always refer service to qualified personal.

 

[OTO1702]

I work for ABB as P. Eng into power panel in power distribution field. I am always aware of safety.

It is very important to look about safety, An other thing very importantis that even pro's and qualified people always works by two or more in the same room. Safety stays the most important thing !

Regards,

Othmane