Polaroid 660 Sun Troubleshooting

[JADoss23]

I recently acquired two different, identical Polaroid 660 Sun cameras. Both look great, no corrosion or anything but untested. I had recently bought a pack of Impossible black and white 600 film to use I a cool cam that I had and when after taking two pictures with the camera both pictures came out blank. I thought this to be a camera error so I took the film pack out in the dark and slide the test strip back into place to try and reuse the film. After a week or two I tried using that same pack of film in both 660 models and nothing discharges at all. Any idea if the battery pack could've gone bad already or am I just unlucky and have three bad polaroids. thanks!