Trouble getting a slave strobe to fire

[Tdnash]

I just received a strobe set for Christmas. Neewer 250 DI. I connected the wireless hotshoe triigger, and the flash the trigger is connected to fires when I trip the shutter, but the second one — the slave unit — won't fire. Any suggestions?

 

[tirediron]

Is the optical trigger on the second unit switched on?

 

[Tdnash]

Tirediron:
No real instructions came with the unit. There is a red light on the top that is labled optical control and anti-preflash switch, however, it does not turn or pull out or press in, and no, it is not lit up.
The the three-position switch labeled "slave" as a "pref" position, "off" position and "nor" position.
I have tried it in all three.
What am I missing?
The description in the listing where I bought specifically said only one receiver was needed, but if I buy a second receiver should that work? Do I have to have the same brand receiver as the trigger or just the same number of channels?
I am new to studio lighting/strobes and am totally at a lost on how to remedy the problem

 

[tirediron]

That "light" should be your optical trigger. Set the switch on the unit without the trigger to "slave" and try again - make sure that your lights are positioned in such a way that the flash from the master unit will iluminate the slave. If that doesn't work, trigger your on camera flash right at it, and if that doesn't trip it, you may have a deffective unit. You should NOT need a second receiver.

 

[Tdnash]

Thanks for your help. I still haven't gotten it to work, but I will keep trying

 

[Jamen]

Hey Tdnash, I have had the same problem and have just discovered the issue! Here goes:

The optical sensors on each light are indeed the little red bulbs on top of the units, but they are triggered through infra red (like a TV remote), not the flash. The flash seems to disrupt this signal. All you have to do is literally cover the little red bulb with something thin like cloth or black tape. This will still let the infra red signal be received and keep any flash light out from flooding the signal. Give it a try! Just use your hand and it will work!

Let me know how you go!