I had a backup Yashica T4D (date) which I tried to sell on eBay. I thought it worked, but the buyer did not, so I gave her a refund. I’m pretty sure it works, so I decided to disable the date function non-destructively, in case anyone wants to resurrect it. Turns out it’s really easy. You’ll need a small Phillips head screwdriver, some black electrical tape, and an Xacto (or similar) knife.
Open the film door and look at the film pressure plate (that bumpy plastic rectangle in the middle of the back door). There are four small Phillips head screws, one on each corner (circled in red in the photo above). Remove them.
The pressure plate comes right off. Set it aside and keep an eye on those little screws. They have a tendency to disappear. Now you can see the window that shines the date onto the film. It’s at the top because, if you recall, the T4 exposes frames “upside-down” so the top of the camera corresponds to the bottom of the frame. All this stuff you see is plastic but relatively sturdy.
Now, put it all back together. All you really have to do is flip the square of plastic with the LCDs in it back over, place the pressure plate back on it, and put the four screws back in. Note that at this point, I’ve lost the little rubber button pad (the one that you attack with a ball point pen from the back of the camera).
As you put it back together, note that there’s a little channel that this ribbon cable settles in (circled in the photograph above).
Holding the camera so its two halves are at a 90 degree angle will help you keep the ribbon cable in the channel while you screw the pressure plate back on.
I told you I lost the button pad! I’ve since found it and will reinsert it.
I’ve loaded a roll of HP5 Plus into it and will let you know how it goes.