Canon 600EX-RT won't turn on at all

[jimlopes]

I own two 600EX-RT speedlite's.  One of them hasn't been used much and is totally dead.  I tried half a dozen different batteries and won't turn on.  

My 2nd speedlite turns on, but sometimes it doesn't.  The led screen sometimes is looks like it half on.  So this flash is proving to be unreliable on a shoot.

Canon has stopped supporting this version so I can't even get these repaired.  Is there a reset button on the device or anything else I can try to revive them?  Thanks

[rs-eos]

Were they stored with batteries in them? If so, shine a light in the battery compartment when empty to see if any corrossion exists on the terminals.  Also inspect the terminals on the inside of the battery terminal.

It's sounding like either no power, or only partial power is getting to the circuitry.

[jimlopes]

This flash was stored without batteries.  I typically take them after after a shoot to prevent them from leaking.  The contacts look clean to me.  What do you think?

[jimlopes]

I also tried cleaning the contacts with rubbing alchohol just in case, but didn't help.  Any other way to revive this guy?

[normadel]

About batteries.....a number of years ago I had a Canon 420EX flash (actually I still have it) that quit turning on. I checked the batteries and terminals and all looked clean.  Sent it to a repair service to see if it was save-able. They sent it back working, with a note telling me that the batteries I was using, Duracells, were prone to causing a barely-visible film to form on terminals. All it took was cleaning the terminals, and a recommendation not to use Duracells but to use Energizers. I have used only Energizers ever since.

[jimlopes]

I just tried cleaning the terminals with rubbing alchohol but that didn't help.  Never knew about the duracells, so that's good to know, thanks for that.

[rs-eos]

Bummer.  Agreed they look clean and I didn't know about the Duracell batteries.  The only batteries I used in them were Sanyo (and then Panasonic) Eneloop rechargables.

[normadel]

I can't say that the Duracell thing is still valid, just relating what a repair shop's experience was then.

I too don't use alkalines at all in my flashes anymore. I have Energizer and Eneloop rechargeables.  

I'll also use lithiums, even though Canon warns against them in their flashes because doing rapid flashes can cause dangerous overheating.  So I don't do rapid-fire flash shooting. Here is a good article about powering flashes and AA batteries:

https://www.scantips.com/lights/flashbatteries.html

[wq9nsc]

The terminals look OK to me also but try a little WD-40 sprayed on a cotton tip to wipe them down.  WD-40 is primarily light distillates of petroleum with a little light lubricant thrown in and it makes an excellent contact cleaner and will cut through film that alcohol will not.

WD-40 also makes a product specifically labeled for contact cleaning that is effectively the same compound except it doesn't have any lubricating property but it is harder to find and more expensive.  The lubricant used in WD-40 doesn't negatively impact contact conductivity, it became my cleaner of choice after test and measurement equipment maker Tektronix tested a number of specialized cleaners and recommended regular WD-40 especially for their extremely expensive precision 10 turn potentiometers used in their lab grade scopes which even in the 1970s cost well over $100 each to replace.

NOTE: Don't just spray WD-40 inside, spray it on something else to wipe the contacts.  Although it won't hurt most plastics, don't chance it.  And until it finishes vaporizing, it is highly flammable so don't use near open flame.  When manufacturers started using light duty diesel engines in passenger vehicles in the 1970s, some of them recommended WD-40 as a safer alternative to ether for cold weather starting.

Rodger

[jimlopes]

Thanks for that info.  I actually have a WD40 precision pen which is great instead of the spray for door hinges, etc. and for this case of cleaning the speedlight contacts.  I tried that but unfortunately it didn't do anything.  This thing is dead as a door nail. It sat around for a couple of years during covid and its hasn't been used a lot since I bought it as its mostly my backup.  So I'm surprised it doesnt turn on at all even though it hasn't had heavy use.