View Full Version : Speedotron 2401A Indicator Light Bulb

24-Feb-2019, 17:24
My Speedotron 2401A power pack ready indicator light bulb doesn't work. Does anyone know the model number of this kind light bulb? I couldn't find any information online. Please let me know. Thx

Peter De Smidt
24-Feb-2019, 17:59
Maybe call Speedotron service? Or another flash service provider? Note that opening up these packs is very unsafe if you don't know what you're doing.

Bob Salomon
24-Feb-2019, 18:03
Maybe call Speedotron service? Or another flash service provider? Note that opening up these packs is very unsafe if you don't know what you're doing.

Unsafe is one way of saying that it could be fatal!

Peter De Smidt
24-Feb-2019, 18:37
I did say "very" :) I agree with Bob, though. In any case, doesn't your pack beep when charged?

24-Feb-2019, 19:02
I think these don't have a bulb, but a glow tube under the panel (I'd have to check mine), but not user replaceable... They don't usually go bad but they can in rare cases... A tech can replace that as the tube is fairly generic, but they better know what they are doing inside to avoid surprise death as mentioned...

But on the other hand, strobes recycle fully quickly, so if you are not doing a motor drive fashion shoot, just allow a few seconds from the last pop, and you should be fine...

Another tip from a strobe tech was to leave the recycle time switch in the slow setting, as these packs are getting older, this puts less strain on the strobe pack, and the power outlet + building wiring...

Steve K

24-Feb-2019, 19:16
I'd definitely call Speedotron. They'll tell you if its user replaceable or not. They sold me the little bulb for the ready bulb for my 2403B pack, but I believe the 2401 is different. They can certainly tell you whether you can do it or need to send it in.

25-Feb-2019, 06:43
The Speedotron 2401A doesn't have beep when charged.

I unscrew the color plastic cap to reach the indicator bulb. It's easy unmounted the bulb, but shape is very rare. And it's not the screw mount of indicator bulb, but size is small.


26-Feb-2019, 18:50
Can the indicator bulb be removed when the plastic cap is unscrewed? Speedotron uses a lot of standard industrial components, the bulb is probably easily sourced. Post several good quality photos of the bulb if you can remove it.

25-Apr-2019, 14:18
You sometimes have to replace the whole housing, not just the bulb on those things. That requires soldering and soldering around some dangerous capacitors. Also, you have to measure the bulb ahead of time to find out how it's being supplied. In other words, is it a low voltage incandescent DC light or a higher voltage AC neon light? I've replaced these on a couple of power packs before.

But before attempting any of that (which is very dangerous), you might want to test the rest of the circuit first. Usually those bulbs don't go bad when they quit working. Usually it's something else in the circuit that quits working properly and that causes the indicator bulb to quit functioning. Sometimes there's a trim knob on a small potentiometer inside the unit that adjusts the threshold for when the light comes on. And the threshold may not be being reached because the capacitors are too old and not holding a full charge anymore. So even if you did replace the bulb, it still wouldn't come on.

My point being, it's probably a good idea to have someone who knows what they're doing look at it, even if it is an easy, user replaceable part. Because chances are good that that's not the actual problem, but rather just an indication of another problem in the circuit. And that's an old power pack. It could probably use a good once over by now and have those old caps replaced (which is definitely not something you want to do yourself).