Nikon SB-900 Flash Trouble

Bgagnon127 · Jun 8, 2015

Hi Everyone,
I photographed my first wedding of the season this past weekend and my Nikon SB-900 Flash unit started acting erratically. More specifically it is randomly not firing, and towards the end of the night it would fire but the exposure did not capture any of the flash, leaving it extremely under exposed. My shutter speed was 125th/s which should be well within the range of the flash, right? I've used it with these settings for years without issue.

I had it in TTL mode all day and replaced the batteries thinking they might have been low. Still didn't work correctly. I then switched it to Manual mode at 1/4 power and it worked. I also tried resetting the flash to factory settings but this didn't seem to help. Does anyone know if this is an issue with a camera setting, or is the flash unit starting to fail?

Thank you,
Brian

tirediron · Jun 8, 2015

Are you 100% certain that the flash was fully seated and locked on the hotshoe/TTL cord?

Microbois · Jun 8, 2015

If I'm not mistaken, the SB-900 flash has been replaced by the SB-910 because it had issues. I don't remember what was wrong with it, but I think it was overheating, and leading to some problems. Do you still have those problems now, once it's cold again? It may have been damaged by heat if you used it a lot during the wedding.

Bgagnon127 · Jun 8, 2015

tirediron said:
Are you 100% certain that the flash was fully seated and locked on the hotshoe/TTL cord?

Yes I'm sure that the flash was fully seated. Thank you for responding.

Bgagnon127 · Jun 8, 2015

Microbois said:
If I'm not mistaken, the SB-900 flash has been replaced by the SB-910 because it had issues. I don't remember what was wrong with it, but I think it was overheating, and leading to some problems. Do you still have those problems now, once it's cold again? It may have been damaged by heat if you used it a lot during the wedding.

Yes this flash unit does tend to over heat but I have it set so it will warn me before it gets to the point that it damages the flash. I will look into this further though. Thank you for the response.

tirediron · Jun 8, 2015

Check the foot, ensure that all the contacts are as they should be (they should push and spring down slightly); is the behaviour the same on other camera bodies?

Derrel · Jun 8, 2015

I the past, there have been some problems with Nikon hotshoes allowing flashes to "pull away" from the camera body the slightest little bit; this was an issue with a number of D700 bodies. That occurred a couple years back; high-volume flash shooters (wedding people mostly) with D700 and D3 or D3s dual camera setups were noting that their flashes would often not fire when shooting "talls" with their D700 bodies. So, there is that possibility.

There's also the probably MORE likely issue of batteries that are not performing right. You mentioned changing the batteries--how many times did you change them? Are you running off of just 4 AA cells? You mentioned that 1/4 power manual worked, and fired right: that makes me think the issue was inadequate battery charge level/battery fatigue. You have left out a lot of details that would be important to diagnose the problem, like what ISO level is the camera and flash set to? What f/stop were you working at? How fast were you shooting? How are you shooting? Bounce? Straight ahead? If the ISO level is 100 to 160 and the venue is big, and you are bouncing, then EVERY SINGLE frame is almost assuredly a FULL capacitor dump, max-power flash pop....after 50-60 of those in a short while, 4 x 1.25 Volt AA batteries will be so tired that you'd need to wait 35 to maybe even 45 seconds between flashes--OR change batteries. If even ONE of the cells was a bit sub-par, your recycle times would lag terribly.

Again...if the flash fired well and right at 1/4 power manual, then there could be issues with the distance the flash had to go, the f/stop in use, and the ISO level,or batteries, or any combination. LOW-ISO flash at an event cannot be handled right with just 4x 1.25 volt rechargeable batteries, and needs at minimum the 5th battery added, or an external power supply like a Quantum.