PowerBook 3400c Selector

By selector, do you mean the trackpad button?

If so, it's actually-from what I understand-it's not super uncommon. I know mine didn't work when I first got it. There is a microswitch attached to the bottom of the button, and it pushes against a piece of plastic to "click." On mine, this piece had broken off-I rebuilt it with superglue and the button now works.

One of the best things you can do is pull off that part of the case and just see what's going on. If you take the keyboard off(take out the three screws on the bottom and you can then lift up the keyboard), you should be able to pop off the trackpad and palmrests as one unit. This is attached to the board by a single ribbon cable, and removing that will allow you to examine it.

As for the accessory door-I have two of these computers(one working, one for parts) along with a Kanga. The Kanga is basically the same computer but with a G3 processor(in fact it's sometimes called the 3500). None of them have the accessory door.

 

Back covers of PB 5300 or PB 190 can also be used, but I don't believe you can buy NOS covers after 20 years have gone.

 

Before buying the part, look at what's going on with the one you have now. It may be an easy repair. I used superglue and then followed up by "welding" it with a soldering iron.

I've also seen at least one picture on the internet of someone who made a replacement out of aluminum.

 

BTW, here's a photo of mine before repair. Notice the broken piece of plastic lying NEXT to the microswitch.

 

This thread makes me want to take out my 540 and start fixing it up.

Really nice 3400c though, I'm jealous!