Hi Broxibear,

In my reading, _nearly_ everyone has the problem, except for Nikon support people - who never heard of it. :-0

Which makes me wonder why there's an override in the system.

Anyway I'm thinking there's an external factor that making everything whacky like a bad shorting connector on the feet of the units. Boot lights going bad at the same time seems like a karma beyond belief.

My best,

Mike

One more thing I forgot to add, I spent a a couple of hours yesterday reading through the various internet posts about the SB-900 overheating (I just bought one a few weeks ago so wanted all the info I could get on it) and not everyone had the problem... there were many who didn't experience any issues at all with their flash.
I also googled "Canon 580EXII overheating" and guess what?...it too overheats when you push it too hard.

My SB900 have turned off a few times, I have newer dared to have the thermal protector turned off. I have used other models without thermal protection and most have lucked out not frying them.

I think Nikon should make a SB900 replacement with following improvements:

Double AA batteries with a Li-ion battery EN-EL14 slot (from the D3100), this would generate less battery heat, easier and faster to change battery. The Pentax KR DSLR has a dual battery system

Improve the heat dissipation, even if it adds a small amount of weight

Don`t take this the wrong way, the SB900 flash is a great flash, great menu, great exposure but hard to use at events were continues shooting is required

Back to subject, I hope that you get yours fixed

Pete

Thermal protect is there for a reason. The boards have noted this issue for quite some time. Sorry.

It's a small world...I too am an Auburn alum. War Eagle! and Congratulations to the AU Tigers on winning the BCS Championship!!

But, just stay in line with the topic heading and make this a legit post....I will not be disabling the thermal protection on my SB-900.
Visumax, hope it's something simple 'cause those things are expensive.

Regards,

Rx

Yikes, broxi... I'm taking a break for the halftime.

I'm an Auburn alum (sort of) and former faculty member... My office was across from Jordan Hare. War Eagle!

However, I'm living much closer to Oregon territory - I quack a lot up here. ;-)

The PocketWizards look terrific and thanks for all the info. There's a great little PDF following your link that spells out the works.

Best to you.

Mike

As Broxi says, overheating a SB900 is a well documented issue, I haven't checked yet if there is a thread other than this discussing it (as this hasn't been closed down yet I presume not), my question is do the other manufactures of flash guns that are equally powerful as the SB900 have the same issue? Is this a Nikon design fault, or just inevitable with any flash of this power?

visumax said:
And here is the good part, I was also running new SB700's in the same mode, same settings, and they didn't even get warm!

It helps that the SB700's tube is about half as powerful as the SB900's. If you were, as you said, firing them both at 1/8th power the SB700 should not have gotten even half as hot.

Wow, there's so much on the web about the SB-900 and overheating it's causing my brain to overheat...After reading too much of about it I suggest not turning off the thermal protection, not using rechargable batteries and don't be silly about machine gunning the flash.
Anyway, I'm off to watch the BCS Championship Game...Go Ducks !,I don't have any Oregon connections, I just don't like Cam Newton lol !
Quack Quack !

Hi visumax,

I'm not going to be hard on you. This is the first time I've heard that anyone has had the units go belly up with the protection turned off.

Have you looked at external connections? Not the flash's, but what they were connected to? Other physical things that could cause failure?

It seems too odd that both would TU at the same time. It seems to indicate something more than the thermal drain, that would be a terrific coincidence.

Good luck and my best,

Mike

And here is the good part, I was also running new SB700's in the same mode, same settings, and they didn't even get warm! There is no thermal protector to turn off on the 700's but they seemed not to mind the amount of use that I was requesting from them that fried the 900's!

Yeah, I posted this to warn everyone else what might happen. Interestingly I was running it on manual 1/8 power, about 100 shots in 30 minutes, with freshly charged Eneloop batteries. I have to say, I do not regret turning off the Thermal Protector since it comes on so easily. Mostly I had used the flashes in iTTL and I guess the lower energy of this mode is still much less than 1/8 manual mode. Any suggestions as to the best place for Nikon service?

lauzobe said:
"He's dead Jim"

Also don't forget "you canna change the laws o phisics"! If you turn it off you're on your own.

Hope it's not terminal. As Segura rightly says, a good lesson for all of us.

+1 for what LoveTheBerry said.

Everyone else with an SB-900 consider this a warning about turning off the Thermal Protector. It is there for a reason.

Question to OP . . . how hard were you pushing it and what kind of batteries were you using?

Sorry to post this,...PLease DOUBLE check that the batteries are facing the correct way,...it happens!

You must have been pushing your SB-900s way beyond normal if both of them died at the same time?

"He's dead Jim"

Sorry, I had to say it ;)

Hopefully a days rest will help them.

I have seen others turn the thermal protector off. I have seen them also shell out another $500 for a new one. I hope your situation turns out better. A friend turned the protector off and Nikon would not honor the warranty. Somehow the flash records it and Nikon can tell the last settings.

@Drab - I haven't heard of blown bulbs, just fried electronics.

The LCD screen shows nothing. I have tried pushing the green buttons and this does not help. I also tried to close battery door with power on. It seems like there is no power to the unit.

Have you tried to push down both green bottoms

Pete

I was under the impression that those who ignored Nikon's warning and turned off the thermal protection risked blown bulbs, not complete failure to power on.

I have two SB900's that have the thermal protector turned off and now they will not power up even with new batteries and 2 hours of cooling off. It is interesting that this happened to both flashes the same day. Is there any hope of getting them to work or do I need to send them in for repairs? I know this is why there is a thermal protector, but I found that previously it shut down the flashes too quickly. I was wondering if there is a fuse since there is no power on or did I burn out some circuit board.