[Pandysloo]

Easy for me to say this with hindsight but it sounds as if you bought with a 90 day guarantee and waited until almost the end of the period before trying it and now the 90 day period has expired.

Stating the obvious but with second hand stuff like cameras always run a film through it within a day or so of getting it so any issue surfaces straight away.

I hope the seller will "play ball"

Normally I test things out immediately, but I was only just able to get a lens for it.

The seller said they would sell me another one for 50% credit if I return the one I have. Only problem is, all their other ones are listed as having broken advance mechanisms one way or the other.

I guess I'm stuck trying to fix it myself. I dry fire it at high shutter speeds and see if that smooths it out.

Open the back and point the camera towards a VERY brightly lit piece of white copy paper. (NOTE: The actual film gate and rear of the camera must NOT be in bright light when you do this.) While looking at the rear film gate, fire the shutter. Even at 1/2000 you will see something white and you will be able to tell whether the WHOLE 24x36 gate is open. - David Lyga

Doing this, it appears that the entire gate is open every time.