roger55 Loc: Tampa Bay Florida

I have an older 430Ex flash and a EOS R. There are times the flash won’t fire. Any ideas what might be going on ?
Usually the flash is set at ETTL.

twowindsbear

Here are some ideas of what may be going on:
Flash not turned on. Flash recycling from previous flash. Flash not making proper contact to camera, because flash contacts are dirty, camera contacts are dirty, because connection is slightly misaligned. Flash is nearly at the end of its life. Batteries are marginal. Battery contacts are dirty, or otherwise not making good contact. Camera 'decides' that flash isn't needed & doesn't trigger the flash. Flash has been 'on' too long & has to recycle a bit.

E.L.. Shapiro Loc: Ottawa, Ontario Canada

Thats right! So the OP shod go by the diagnostic process of elimination. Clean the battery compartment and insert fresh batteries in the indicated polarization and properly aligned. If the unit fire consistently by means of the open flash or TEST button on the Speedlight, independently of the camera, the issue is not in the Speedlight but in the contacts in the foot of the unit the hot shoe- clean those and try again with the camera set at the TTL function and make certain the shutter speed is within the correct synchronization range.

To test the integrity of the foot- simply take a pieceof wire or a metal paper clip and short-out the center contact on the foot to the edge of the shoe- the part that makes electrical contact with the camer body. See if it fires consistently.

When cleaning the battery compartment contacts, make sure they are intact and free of scale, corrosion, or residue from leaked batteries. Isoporpal alcohol will remove some dirt and an emery board can help remove residual scale or battery innards. Make sure filings or remaining dirt is removed from the compartment and can not enter the insides of the unit. Be gentle withte the hot shoe, a Q-tip wilt a LITTLE dab of alcohol will remove most kidsof soil. Try not to scrape at it or pour on too much solvent. If alcohol won't work try some electrical contact clean sprayed on a Q-tip. Do not spray this on the camera or the Speedlight.

If the issue is in the internal circuitry of the Speedlight, repair may be costly, beyond the value of the unit, and/or parts and service may not be available for that older model(?) could however be a minor issue like a disconnected trigger wire to the flash tube- that thin one that is wrapped around the tube. If it had a lot of prolonged usage, especially lots of rapid firing, the tube may be carbonized and on its last legs. Intermittent firing could be capacitor issues or somethg else's malfunction on the circuit board.

So, try the less invasive tests and procedures and see if you luck out. Otherwise, it may be time for a replacement.

If you are into electronics and high voltage, you can disassemble it and see what's up. If you are not, remember, that little bugger harbors over 300 Volts when it is fired up. That can cause a fairly serious electric shock if you make contact with a loaded capacitor, it might not kill you but it can hurt, and cause burns or nerve damage. If you happen to touch it with both hands and the charge goes across your chest- that is not good! A cardiac defaulter works on the same principle.

Oh- I hope the issue is not in the camera. Sometimes a defective Speedlight or other flash unt can cause damage due to excessive trigger voltage. Even if the speed light is rated at a low trigger voltage, a malfunction can direct high voltage through the camera. If other flash unts work properly on the camera, that will not be the problem.

hcmcdole

I have an R5, an old 430EX, the 580 EX II, and two different Yongnuo flashes that I used with my Canon 7D and 80D. I've only tried one of the Yongnuo flashes with the R5 to see if it worked (it did). Now I am curious if all the flashes work with the R5.

CHG_CANON Loc: the Windy City

Consider referring to page 166 of the EOS R5 Advanced User Guide, a PDF you can download from your local Canon site. The chapter is "Shooting with Speedlites", covering EL / EX series Speedlites and non-Canon flash units. There are some caveats about the exposure mode(s) that can be used with various series flashes.

amfoto1 Loc: San Jose, Calif. USA

According to the EOS R user manual (page 177), the camera is completely compatible with all EL and EX Speedlites.

They recommend referring to the specific flash manual, as it pertains to "Type-A" cameras.

The EOS R also can be used in a more limited way with EZ, E, EG, ML and TL Speedlites.

User ID

You have put your camera in charge of lighting decisions. Just take over the job and the mystery will evaporate. Do not RTF as that will result in headaches.