I've bought a non-TTL Yongnuo flash (YN-560 IV) for my Canon 77D and it works fine when shooting through the viewfinder. However switching to Liveview mode, I found out that it annoyingly stops working. It is possible to get the flash to fire if I switch to high-speed burst mode, however in that case the flash fails to synchronize with the camera properly. Is there a way to force the camera to sync the manual flash properly?
I've read the answers to this related question, however my camera doesn't have a silent shooting mode, so they don't apply. Likewise the Canon manual says:
A non-Canon flash will not fire during Live View shooting.
However it obviously does if I switch to high-speed mode and the manual doesn't say anything about how to enable proper synchronization.
If you're only wanting to mount the flash directly on the camera's hot shoe, any flash with the four extra pins will work, even when used in manual power mode. There has to be communication between the flash and camera body.
– Michael C Dec 28 '17 at 21:49