I purchased a used Hotronic ap41 from an ebay seller and the ad said it was working perfectly.

I took it out of the box - hooked it up using a consumer VTR - composite video out to ap41 composite input and ap41 output to my capture dongle.

In the bypass mode my video passively passes through the TBC to my monitor BUT when I put in the normal mode I get nothing but garbage on my monitor screen.

The moment I turn the ap41 on I get a constant, erratic flashing of the gunlock led on the front panel. My understanding is that if I am using an external sync source the gunlock led will light a constant red but since I am using a single VTR signal the internal components of the ap41 should take care of everything and, in the normal switch position I should see my video on my monitor and be able to make adjustment with the proc amp controls.

I've sent the seller a message saying it's not working as described in the ad and asking for help, a refund or a replacement.

If anyone with experience with this unit can suggest anything else I can try it would be greatly appreciated. I do have a pro quality beta editor/recorder that has a BNC sync out but with my application I can't imagine why I would need to input external sync to the ap41. All answers appreciated and Thank You Jimmy