I have a canon 70D I was trying to use with a Novatron head/pack lighting kit. Attached the Wein Safe Sync to the hot shoe of the camera, plugged the PC sync cable into it and then into the pack. Flashes didn't fire. Tried it on an older 10D and it worked fine.

Mounted a Canon speedlight on the hot shoe and that worked fine. Using the built in flash to wirelessly trigger Canon speedlights works fine. Tried different settings such as turning off Wi-Fi, messing around with the flash settings. No luck.

Any idea what's going on? Any other suggestions? Has anyone had this work attaching a PC sync cable to the 70D via a hot shoe adapter?

  • \$\begingroup\$ What is the trigger voltage of the novatron head? \$\endgroup\$
    – Michael C
    Jul 27, 2016 at 22:57
  • \$\begingroup\$ No idea but the safe sync brings it down to 6v. \$\endgroup\$ Jul 27, 2016 at 23:18
  • \$\begingroup\$ It may be bringing it down too far... \$\endgroup\$
    – Michael C
    Jul 27, 2016 at 23:19
  • \$\begingroup\$ What trigger does the 70D expect? I called cannon and they told me they couldn't help me. The hot shoe expects a ETTL compatible flash device on the hot shoe. \$\endgroup\$ Jul 27, 2016 at 23:21
  • \$\begingroup\$ I don't know, but all EOS DSLRs are supposed to be able to handle 250V. The 10D may have a lower minimum trigger voltage than the 70D. \$\endgroup\$
    – Michael C
    Jul 27, 2016 at 23:22

2 Answers 2


This is a bit embarrassing as the fix was quite simple.

The Novatron pack I have has a H type (household) plug for the sync cable. Looks like a standard househould electrical receptacle.

The plug can go in both ways and apparently polarity is important with the 70D. After I plugged it in the pack the other way around the strobes started firing fine. It's been some time since I've used this kit.

The initial orientation of the plug worked fine with a 10D and some other cameras as well as my light meter.

  • \$\begingroup\$ +1 for both question and your answer. Don't be embarrassed; it's good that you found the solution and posted it as an answer. It'll happen to other people, and your answer will help other people. It isn't exactly logical that the polarity should be important with a 70D and not with other EOS models :) \$\endgroup\$ Jul 28, 2016 at 10:06
  • \$\begingroup\$ @laurencemadill Thanks. I ran across someone else that had the same problem but couldn't find a solution. Called OmegaBrandess support (they own the Wein photo triggers now) and while they were aware of the polarity issue they didn't mention it since my other cameras worked. \$\endgroup\$ Jul 28, 2016 at 18:55

Some possibilities that may be causing your issue:

  • If you are using Live View be sure that under the Shooting 2 (red) menu you have Silent LV Shoot set to Disable. If it is set to Mode 1 or Mode 2 the flash will not fire. (See pages 194 and 231 of the EOS 70D Instruction Manual for more.)
  • Under the Shooting 2 (red) menu be sure that Flash Control --> Flash firing is set to Enable. (p.195)
  • If you are shooting in Av mode, make sure under Shooting 2 (red) --> Flash Control you have Flash sync speed in Av mode set to Auto. (p.196) When shooting insure that the Tv used by the camera is 1/60 second or longer. Any faster may be too fast for your setup to trigger.

  • Under the Shooting 2 (red) menu --> External flash func. setting --> set the Mode to Manual and the Wireless Function to Off. (pp.199-200) You'll probably need to have an EX series speedlite mounted to access this section of the menu. These settings shouldn't matter, but sometimes with a third party flash it seems to on certain Canon cameras.

  • The Wein Safe may be lowering the trigger voltage too much to a point below the 70D's minimum trigger voltage. Chuck Westfall has been quoted that all EOS DSLRs can handle up to 250V trigger voltage at the hot shoe. I've never seen actual specs on minimum/maximum trigger voltages for EOS DSLRs, though.

  • Insure that all connections to your flash head are good and at the proper polarity.

An alternate option might be to get a cheap pair of manual wireless triggers. Most of them have a PC connector on the receiver that could connect to your novatron head. You can pick a set up for around $30.

  • 1
    \$\begingroup\$ This was very helpful. I ran across the different steps you mentioned elsewhere and tried them without success. Turns out it was user error. Had the pc cord plugged into the pack backwards. \$\endgroup\$ Jul 27, 2016 at 23:53

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