Yongnuo YN560 lll fires only on test

[Rollei1972]

I have tried to fire (pc to pc) my new unit in a Nikon F and an FE. Also on the FE's hot shoe. And, also on my Graflex XL via the sync cable. At first I suspected the pc cable connections. I did a little push on the pins.
I think this may be a defective unit but I am not flash experienced enough to know how to check the pc signal to the flash.
Does Yongnuo have a good record of quality control or...not?
My current frustration tells me to return this to B&H and go to Ebay for a used manual flash.
Any advice from APUG users will be greatly appreciated.

 

[narsuitus]

I just tested my Yongnuo YN 560 IV on my Nikon F2 to see if I could find problems similar to yours. Finding a working PC to PC sync cord in my bag of old sync cords was harder than I thought. However, I finally found one that worked perfectly.

Therefore, if you are sure your sync cord is working, I would check to see if the Yongnuo flash mode is set on Manual Mode and not Slave Mode.

 

[Rollei1972]

Another apug member explained how to check the circuit to fire the flash. The flash continued to fail. I think the unit is defective and I will contact B&H today for advice on how to proceed.
Thanks for your suggestions.

 

[narsuitus]

Please post so others will know how to check the circuit to fire the flash.

 

[Rollei1972]

The member suggested by PM that I bend a paperclip into a "U" and touch one end to the center of the PC on the flash and the other to the cylinder to complete the circuit and "flash" the unit.