550 ex flash - smelly hot

This is the best way to describe the issue with my older 550ex flash. I was using it last night, and it started to have a burnt plastic smell. This can't be too good, but it still works. It also has develop some melting on the front Fresnel lens. I had bought this used, so I not sure how old the actual unit is. I used the flash for may be 1000 times without problems. Has anyone seen/heard of an issue with the 550 ex flash? I've been using the flash as the "C" slave background flash. I have two other 580 ex's used as the "A" and "B" slave.

Thanks.

Did you flash too fast at high powers?

chantu wrote in post #12615649
I was using it last night, and it started to have a burnt plastic smell. This can't be too good, but it still works. .

maybe the overheated flash melted the plastic diffuser in front of the bulb

What type of batteries are you using in it? I ask because I've heard of lithium (not lithium-ion) batteries causing overheating issues with flashes. If you're not using lithiums, then are you noticing the flash is putting out more power than you'd like? I'm thinking maybe there's something wrong in the circuitry that's causing it to fire at higher than its normal max power level.

On a much more simple scale, try just cleaning the fresnel lens. It's possible something (skin oils, etc.) got on there and as you fire away it heats up and smells.

I use some NiMH batteries. I trade off between Enloops, Rayovac and Duracell, and I don't remember which. But you may be on to something. I use the flash tonight and didn't get the smell/burn. I didn't read the posts till just now, so again I don't know which is which - batteries currently being recharged. I'm going to track which batteries (if this is the issue) is giving me the burn.

KaBlookie wrote in post #12617327
What type of batteries are you using in it? I ask because I've heard of lithium (not lithium-ion) batteries causing overheating issues with flashes. If you're not using lithiums, then are you noticing the flash is putting out more power than you'd like? I'm thinking maybe there's something wrong in the circuitry that's causing it to fire at higher than its normal max power level.

On a much more simple scale, try just cleaning the fresnel lens. It's possible something (skin oils, etc.) got on there and as you fire away it heats up and smells.

All of those batteries should be fine. I just heard/read that straight lithium batteries will heat up a lot when used in short but high discharge applications (like flashes...use a LOT of energy in a very short time, over and over and over again).

If you get the smell again, I'd see if you can narrow down whether it's coming from the flash bulb area or the battery area.

Did you fire too many shots in fairly rapid succession? Canon has specific warnings in its owner's manual for how many consecutive flashes before allowing it to rest and cool a bit. Even LOW power (like stroboscopic mode) has limitations to the number of consecutive flashes before allowing some cooling!

I was shooting one-at-time shots in a portrait setting. I had 2 other 580 ex I flashes that didn't have this problem. The only thing different about the 550 in the setup is that it was the "C" slave (with 0 EV comp.), and the other two flashes were slave "A" and "B". I was also in ETTL mode.

Wilt wrote in post #12648904
Did you fire too many shots in fairly rapid succession? Canon has specific warnings in its owner's manual for how many consecutive flashes before allowing it to rest and cool a bit. Even LOW power (like stroboscopic mode) has limitations to the number of consecutive flashes before allowing some cooling!

I still can't understand why photographers use lithium batteries in a high-power application like a flash. I have 3 or 4 sets of rechargeables.