My Arri 300w keeps switching off (bulb is fine), either:

(a) (particularly) when I turn the spot/flood dial;

or

(b) all of a sudden, for no apparent reason.

I can hear a slight sizzling sound (I didn't touch any of the bulbs I've inserted) when the light's on too. I'd really appreciate any help sorting this out.

That's a common problem with Arri 300 and 150, I owns several and they all required some attention to the wiring.

There could be two problem areas, the first is the terminal block, that's a small square inside the light where the main and the lamphouse wires are attached and secured by set screws, those screw might be loose and the wires make bad contact or worse it could short out. Try removing the lamp, move the focusing carriage forward and see if you can get to those screws. Most likely you'll have to take the light apart.

The second problem is that the wire breaks internally at the stress point, that's where the cable enters the light. With the light on and on a stand move the wire and see if the light goes on and off, if it does that's most likely where the problem is.

If you are not handy with tools then I would suggest sending it to a repair station. If you are handy with tools and with minor electrical connections you can fix it by cutting off about six inches of the cable and rewiring the unit. If I recall those cables are not cheap.

My Arri 300w keeps switching off (bulb is fine), either:

(a) (particularly) when I turn the spot/flood dial;

or

(b) all of a sudden, for no apparent reason.

I can hear a slight sizzling sound (I didn't touch any of the bulbs I've inserted) when the light's on too. I'd really appreciate any help sorting this out.

Yep, we just took two of our Arri 300s to Arri in Burbank for the same issue. Covered under warranty, they had them for about two weeks.

D

Thanks for responding, it's always great to know that you're not the only one.

I'm not the handiest with tools, but will have a look at the easier stuff mentioned (screws and wires I can handle!) and then get it professionally repaired if necessary.

Thanks for responding, it's always great to know that you're not the only one.

I'm not the handiest with tools, but will have a look at the easier stuff mentioned (screws and wires I can handle!) and then get it professionally repaired if necessary.

If I was out of warranty and had the time, I would just re-wire it myself but since these were under warranty, why not let Arri deal with it?

They are not difficult to re-wire, just takes some time to troubleshoot. Unfortunately time is at a premium these days with me ;-)

Dan