Paul C. Buff, Inc. Technical Forum

Hello, I have a Canon 580ex with a Vello PC +Top Shoe converter when the CyberSync CSRB Receiver is connected, nothing happens. When I press test on the Transmitter the green light turns red on the receiver but the flash doesn't fire. Thank you for any help with this problem.

Remove the flash from the Vello.

Place the CST into the Vello

Press the test button on the CSRB. Does the LED on the CST fire? If yes, then there is a setting on the 580 that is incorrect.

If not, unplug and replug the cord fram and to the CSRB. Does the action of plugging or unplugging trigger the CST (as indicated by the LED)? If not, then the the cord or the Vello is bad.

You can try a different cord on the Vello, and/or the cord on a different device. The CST should have come with a PC to 2.5mm cord.

Remove the CST from the Vello and replace with the 580. Connect this cord to the CST and the Vello. Press the test button on the CST. Does the flash fire? It should and failure to do so would indicate a bad Vello. By flashing, this would indicate a bad cord previously used.