Help! Light repair: Arrisoft 1000 tungsten fixture

Simply Cinema

Simply Cinema

Active member
Hey everyone,

I figured I'd try my luck here. I've got an Arri 1000 watt Arrisoft light that keeps blowing bulbs on me. The bulbs don't blow right away, but rather blow after some use (about an hour or two). There doesn't seem to be any symptoms besides the blown bulbs, and it isn't caused by moving or bumping the light. I'm trying to see if anyone else has had this problem or knows a possible remedy.

This light uses the FCM 1000w bulbs. The bulbs don't seem to blow in the actual filament part, but rather at the edges where there's a small area of ceramic. (see photos)


As of now, I've tried doing the following things:

Replaced the power cable and plug.
Redid internal wiring (new connectors, original wires)
Made sure not to handle bulbs with bare hands.

If there's any DVXUser out there that can help, please reply here. Thanks in advance!

Here's a pic of my most recently blown bulb:
View attachment 79298

Here's a pic of the bulb housing:
View attachment 79299

Here's a pic of the internal wiring:
View attachment 79300
 
There's really nothing more than the AC wires going directly to the lamp, well aside from any inline switch, possible fuse, and additional wiring.

Try lower wattage lamp for test, and see if it blows. Maybe your issue is related to more heat or current.
 
They're failing at the pinch which suggests over temp (blocked vents??), or just a poor batch of lamps
 
Yes I have tried a few bulb brands, doesn't seem to make a difference.

Maybe it just is overheating. These lights are known for getting hot.

i just got back from Home Depot with a new switch and new wiring for the internals. Keep the suggestions coming, guys. And thanks to those who have responded.
 
if the light passes a test and tag service then the wiring should be ok

it appears to me that it is an overheating issue

check that the contacts inside the ceramic holders are clean and clear of pits caused by arcing which can cause overheating

if necessary clean them up with a small file or replace them

cheers
 
Ian,

Do you know how to replace these contacts? Looking at the Bulb housing, it seems like they're all one piece. And since this light is no longer in production, finding spare parts has been a royal PITA. Thanks again everyone for all your help!
 
I agree with Ian. Switches and wiring are not the issue. It can only be three things:

1. Defective bulb manufacturing
2. Heat at the connector due to high resistance, corrosion
3. Here's a stretch - Are you running it on a line that is over-voltage?

[edit] Take a look at construction lights. See if you can adapt a new set of contacts from one of them.
 
Thanks Paul and Ian. I went and bought some solution to remove electric corrosion and scrubbed the contacts with that and a wire brush. Can't do much testing though, as I dropped my last bulb and broke it. Doh!

i have new ones coming in the mail and will post back with the results.
 
were the contacts corroded or pitted ?
i would go with poor bulb manufacture, the "putty" that seals the glass to the ceramic breaks down and allows the filament
to break. there is usually no visual evidence of a broken filament as it is covered by the "putty"
there is not much you can do about that but buy name brand bulbs and hope for the best.
handling them gently and avoiding transport shock will help.

the ceramic holders and leads to the power block are one piece and can be removed by drilling out the rivets and disconnecting the leads from
the power block and removing the whole fitting. it is the bright silver part that encloses the ceramic holder in your pics.
this is a "p.i.t.a" and is only done if the contacts are corroded away or the ceramic is broken.
these should be available. i have to do it with my blondies occasionally.
i would polish the contacts first and make sure the lamp is seated cleanly in the ceramic holders to avoid arcing.

cheers
 
Ian,

The contacts didn't look exceptionally bad, but I'm no expert. Regardless, they're definitely cleaner now. I'm waiting on new bulbs to come in the mail.

I picked up a small packet of bulb grease from the local Autozone. Do you think it would be good (or bad) to put a dabble on the ends of the bulbs to help with connection?
 
the contacts should look smooth

i have never used any grease on the contacts i would assume it is high temp otherwise it will start melting and smoking and could stain the reflector.
if the contacts are are making good contact it is really not needed imo

cheers
 
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