Paul C. Buff, Inc. Technical Forum

I have one AB800. Recently it started firing intermittently, firing once every couple of shots, then every 10-15 shots, now it fires once in every 50 shots. Tha same thing happens when I press test button, the ready button lights, but the strobe doesn't fire. Could it be that I need to buy new flash tube, even if it still fires occasionally?

It is possibly a flash tube, but it may be more. First, shut the unit off and unplug it. Wait for about 10 minutes or so and remoe the flash tube by pulling straight out, gently rocking if neccessary (it may be helpful to remove the modeling lamp as well by unscrewing counter clockwise). Once the tube is out, look for scorching at the tips of the metal leg (inside the glass where the legs are formed, there will be a burned look, this is normal). If there is scorching, then the tube has come loose and arced, burning the leg as well as the contact inside the head. If a leg is broken and stuck inside or the tube will not come out at all, the arcing has likely welded the two together. If this arcing has occured, the unit will need to be repaired.

If no signs of arcing are present, inspect the flash tube for any cracks (they may be very fine cracks) or breaks in the metal wire or bands on the tube. Of course, any cracks or breaks will require a replacement tube.

If you have another Alien Bee, and there is not arcing, you can swap tubes to see if the problem lies with the tube or the head.

I removed the flashtube, nothing is scorched, legs aren't broken. I carefully inspected it for cracks, and couldn't find any. Strobe still fires once every 10-50 shots... And I used it for only a month or so, couple of times a week...