I recently purchased two broken Canon Elan7s: A Elan 7NE with a broken lens release pin, and an Elan 7E that wouldn't turn on. I got them for about 20$ each, figuring I could fix one or both or use one for parts. Little did I know I'd have two perfectly working cameras that I now need to find lenses for...
Starting with the 7NE, all that was required was taking it all apart and bending the pin bracket a little. It needs to be at right angles. Additionally on this camera, the grip was suuuuper sticky. I tried isopropanol, but the paper towel took the black off of the grip and left it even more sticky. Covering it in corn starch fixed that however! And I can even get it wet and it stays not sticky.
The Elan 7E was a little bit harder to diagnose. This camera refused to turn on. I hit it. I banged it. I moved all the dials. I popped the flash up. Nothing worked, so into the camera I went. Not too many progress pics from this operation. I got down to all the rigid/rigid-flex/flex PCBs, and started probing.
I had continuity from the negative battery to chassis ground, so that wasn't the issue. Next I started looking for VBattery from the battery terminal to around the board. I found it right in the front to the left of the lens mount, so I figured the problem was deeper. I purchased a copy of the service manual, and found the one fuse in the camera. It is a yellow box above the battery terminal, general area circled below. It looked like a tantalum cap, so I thought nothing of it not having continuity. I unsoldered it, and replaced it with an equivalent 30AWG wire, and it seems to be working just fine!
When you take it apart, note there are 3 types of screws. Long black, long silver, and short black. The short and long screws aren't interchangable, but the long silver and black are. Use the silver screws for everything inside, black outside. I had only one screw left over (Which is pretty good for ~30 scews). Be careful pulling out the shutter screw, there's a capacitor on a piece of flexPCB that is very delicate.
If your camera doesn't turn off and the flash doesn't work, you need to make sure the top cover ribbon cable is connected all the way. I had to take it apart a few times.