It looks like something is causing the overexposure of your movie.
It's not because the camera did not do it before that something did not go wrong, especially since it still seems to be doing it now. This also applies to your treatment laboratory.
Some points to check:
- Does the aperture stop at the selected setting just before the shutter is opened? The link in a Konica Hexanon 40mm f / 1.4 broke once on me and I almost went crazy by testing the camera counter trying to find out what was wrong before discovering the problem posed with the lens.
- Does the shutter work properly? Or can the second curtain be too slow? If you can find a store that still does, consider having the shutter sync tested.
- Does the film speed selector work properly? Is the same scene measured differently if you change the movie speed setting?
- When was the last time you tested / changed the battery of your photometer? If you leave the lens cap on a lens attached to your camera, or let the light shine in the viewfinder, the battery will discharge fairly quickly (over days or weeks).
- Another common problem is that the connection between the battery holder and the wire leading to the measuring circuit is corroded. Cleaning and resoldering will sometimes solve a problem with the meter.
- If you have a store in your area that does, have the meter tested.
If you have not correctly developed a roll of one of your other cameras since the two rollers of your K1000 have come back overexposed / overdeveloped, also check with the lab that they are not going to be overdelivered. have not changed anything. Someone may have accidentally mixed a lot of too much developer or used a type requiring a shorter development time, whereas he was thinking of using another requiring longer development times.