5D Mark IV won't fire flash

[malofx]

Here is the situation, I've have an Olympus flash, I paid around $500 for it, like 8 years ago. I just started using it about 2 years ago, the flash had been working fine with the 5D Mark IV, but after I dropped the 5D it stopped working, the flash does work with the Canon 80D and others.

Other flashes don't work with the 5D, I sent it out for repair, but they claim there is nothing wrong with it, the 5D does fire a Canon flash, which is what they used.

The 5D should be able to work with any brand flash.

I already set all settings to manufacture settings.

What do you guys think its the problem?

Thanks in advanced.

 

[Darmok N Jalad]

Does it look like all the hot shoe contacts are clean on both camera and flash? Maybe one has some corrosion/oxidation on it that is keeping it from firing.

 

[malofx]

Does it look like all the hot shoe contacts are clean on both camera and flash? Maybe one has some corrosion/oxidation on it that is keeping it from firing.

Hot shoe looks clean, and I sent it twice to be looked at.

 

[steveash]

The centre contact point is the one that fires general flashes, the other contacts are for other controls which are brand dependant. It is possible that the centre point isn't working and that Canon flashes are fired from the other four contact points.