Spent 3 hours chasing a light leak on a customer's AE-1 that turned out to be the red window seal
Got a Canon AE-1 in for a CLA and the guy said he kept seeing a weird orange streak on the left edge of his shots. I checked the shutter, the mirror box, the lens mount, everything. Tore the whole thing down twice looking for pinholes in the curtain. Then I finally held it up to my bench lamp with the back open and saw it, the foam around the film counter window was completely gone. Four minutes to cut new foam, 3 hours of my life I'm not getting back. Now the window seal is the first thing I check on any old SLR before I even touch the shutter. How many of you have a go-to spot you hit before you start pulling things apart?
That line about the foam being "completely gone" is the part that always gets me, because that stuff doesn't just vanish, it turns to dust and you never notice it falling out. So here's my question: when you find a seal that's turned to powder like that, do you just replace that one spot, or do you go ahead and redo every seal in the camera since they're all the same age? I've been burned too many times fixing one leak only to find another one three rolls later.