Paul C. Buff, Inc. Technical Forum

I use 3 X800 units and I fire them from an RF transmitter on the camera. My main light has the receiver and the other 2 units fire using the built in slave sensor. On my last 2 locations, after all units were firing consistently, one of the slave units would occasionally fail to fire and would beep when it received the pulse. So, I assume that the beep was a warning that it did not fire, but what is the condition of the unit when it sometimes fires and sometimes does not?

If it only happens during a triggering episode, then the flash tube is the likely culprit. It may simply be going bad, but more likely it is either broken or it has come loose. I would recommend inspecting the tube. With the light off and unplugged for about 10 minuts, use a clean glove or cloth to remove the model lamp (it unscrews like a regular bulb) and also the flash tube. The tube pulls straight out, but it can be rocked gently to remove it. Check to be sure all wires, bands, and leg are intact. Also, be sure the legs are not charred. If everything looks OK, you can re-install the tube and model lamp and re-test (Be sure to install the insulators, if included. These look like a milky white straw). If there is any breakage, the tube will need to be replaced. I the legs are charred, then the tube has arced, and it also damaged the flash unit, and it will need to come in for repair. Note: there will be some burnt-ish areas inside the glass near the legs. This is normal and where the impurities are burnt off and collected.