New Arri 650w Fresnel sizzling noise

S

SuitcaseSteve

New member
Hi Everyone,

I'm in the process of lighting for a small studio (mostly shooting interview subjects against a white backdrop). I have limited experience with studio lighting, but I have done some stage lighting (mostly PAR lights) and have worked several times with 300w fresnel lights with no problems.

A few weeks ago, I purchased a new Arri 650w Plus fresnel light from B&H. About a minute after striking the light for the first time, I started hearing a loud sizzling noise coming from the light. I wasn't sure if this was normal or not (I've never experienced it with my 300w fresnel lamps), so I only ran it for a few minutes before calling Arri the next day to speak with a support person. The tech said that the light shouldn't make noise and asked that I try a different bulb, and send it back for a replacement if the noise continued. So I tried two other bulbs (another 650w by Impact and a 650w by GE), both with the same result.

So I sent the lamp back to B&H for a replacement. The replacement light arrived this week, but a minute after striking I was getting the same loud sizzling noise. At this point, I'm not sure if this is something I should expect or if I've received another defective unit. The light itself seems to work fine, but it's just loud. I haven't run it for more than a few minutes at a time yet. Is there something I should know about the 650w fresnel to prevent/reduce noise (like, do I just need to run it for a little while to let it "air out"), or is this a problem with the light?

Sorry if this is a basic question, but I'd rather be safe than sorry (and Google searches haven't turned up anything).
 
The only time I've heard one sizzle is where the lamp pins were arcing in the holder. Stupid I know, but you have pushed the pins all the way in? Next step is to work out where the noise is coming from. Does it change if you go from spot to flood? Apart from the odd creak as it heats up, mine are totally silent.
 
I just checked the lamp, and the pins appear to be in all the way. I can't push the lamp into the socket any farther.


The noise is louder on spot than it is on flood. This was also the case with the previous light. The noise takes about a minute to start and then continues for several seconds after the power is turned off. Seems to me to be a reaction to the heat.
 
Second the arcing as the cause. Look at the pin sockets and the lamp pins for any signs of blackening or pitting. If the lamp is seated all the way it could be a bad socket. Does the lamp seem to flicker at all?
 
I don't seem to be getting any flickering from the lamp. I swapped it out for one of the other lamps, and the sound is a little quieter but still there. The socket looks fine at a glance, and I don't see any noticeable blackening to any of the pins (granted, I've only run any of them a couple minutes at a time).

All of the lamps have little nubs underneath on the four corners. That's the only thing I can see that would prevent the bottom being flush with the socket. Are those normal?
 
I heard a sizzling with two new 650s. To me it wasn't loud but I think it was the probably the same thing. I left them on and it went away and doesn't happen anymore. Sometimes dust and other stuff are near the lamp from shipping. Although nerve racking, I would leave them on for a while and let the dust/whatever it is burn off
 
If the sizzling continues after power is cut, then scrap the arcing idea. It has to be heat. It's possible that all it is, is some silicon filler that's been used to protect something - lens clips - see if they have been protected with silicon. One of mine has the metal clip holding the lens in protected with a pad of white. It cures after a while. I guess it could also be simply moisture that needs burning off. Plug it in and leave it for an hour or two and see what happens.
 
paulears said:
If the sizzling continues after power is cut, then scrap the arcing idea. It has to be heat. It's possible that all it is, is some silicon filler that's been used to protect something - lens clips - see if they have been protected with silicon. One of mine has the metal clip holding the lens in protected with a pad of white. It cures after a while. I guess it could also be simply moisture that needs burning off. Plug it in and leave it for an hour or two and see what happens.
Click to expand...

I second the idea to let them "Cook off" for a while and see if the problem stops. I have had to do that with new lights and when I take lights out that have been in storage for a while (It burns off the dust). I would take the lights outside, away from flammable objects.
 
Sounds to me like its just the new lamp 'burning-in'. I've had to do this with my fresnels, just leave them on for a couple of hours.
 
Thanks everyone. I ran the fresnel for an hour earlier today. Started out with the loud sizzling like usual, but by the end of the hour it was completely silent and working like a champ. Seems like whatever it was that was causing the noise burned off.
 
Bought my first ever arri 650w,had the same issue,I was quite paranoid so I called the support and they decided to check it at the w/h. Obv nothing was wrong,the bulb just has to burn in as heat expands all metal parts. ;p
 
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