Help! Sony A6400 shorted hot shoe?

[pytn3]

My A6400 has been giving me this error message in rapid spurts (sometimes stops for a minute or so):

"This accessory is not supported by the device and cannot be used. Please verify the compatibility with the device."

There isn't a flash, or any accessories mounted in the hot shoe.

This started happening (not immediately) after a friend lent me a Vivitar Zoom Thyristor 3500 to do a couple of quick photos with. I think the flash is only 8.9 volts.

I have tried:
Switching batteries
Taking hot shoe cover off
Drying mount with a fan
Gently cleaning hot shoe mount with alcohol

Nothing has worked, and I'm scared I fried something in my camera. What happened? Can I unplug the hot shoe mount cable and get rid of the error messages? Or will that cause more errors? (I don't need to use the hot shoe for anything)

[Cameratose]

Sure sounds like you fried something. Try a factory reset, but I don't know if it will help.

This list shows voltages of old flashes, the problem is you have to trust the ability of the volunteers submitting the information to perform accurate testing. Looking at the 3500, three people came up with three different voltages, and the 'safe' column is marked 'Yes' with a question mark. 

3500

Yes(?)

6V, checked w/Vivitar by Bart Nathan, though Bart Daatselaar reported 9.1V from his —, Scott Slayman tried his with varying dedicated models and got varying voltages in the 4-7V range

It also points out older versions of the same model number could be higher. 

Photo Strobe Trigger Voltages

It's really not worth the risk. Even if you don't shoot flash so much that you need a Sony or even a Godox, it's easy enough to find a cheap, safe flash these days for under $50 on Amazon, most with TTL. I would get one and keep it on hand.

Good luck, I hope it doesn't turn out to be too serious. 

[pytn3]

On 4/23/2025 at 5:32 AM, Cameratose said:

Sure sounds like you fried something. Try a factory reset, but I don't know if it will help.

This list shows voltages of old flashes, the problem is you have to trust the ability of the volunteers submitting the information to perform accurate testing. Looking at the 3500, three people came up with three different voltages, and the 'safe' column is marked 'Yes' with a question mark. 

3500

Yes(?)

6V, checked w/Vivitar by Bart Nathan, though Bart Daatselaar reported 9.1V from his —, Scott Slayman tried his with varying dedicated models and got varying voltages in the 4-7V range

It also points out older versions of the same model number could be higher. 

Photo Strobe Trigger Voltages

It's really not worth the risk. Even if you don't shoot flash so much that you need a Sony or even a Godox, it's easy enough to find a cheap, safe flash these days for under $50 on Amazon, most with TTL. I would get one and keep it on hand.

Good luck, I hope it doesn't turn out to be too serious. 

Factory reset didn't work, so I ended up taking apart the camera and unplugging the hot shoe cable all together... and it worked! No more error messages, just a non-functional shoe mount. I wonder if I bent a pin in the hot shoe or something... oh well!