The general concerns:
- are there obvious signs of damage?
- do the controls work smoothly?
- is the bellows intact and does it appear to be free of holes?
- when you focus, does the bellows extend smoothly?
- do the parts that should be parallel (lensboard, negative stage) appear to be parallel, and are they perpendicular to vertical?
- does it power up?
- is the wiring complete and does any of it appear frayed?
- if it is a condensor head (the pictured one is) does it include both condensors, and a filter tray (if it is like mine, the front of the head is a door that slides up and out, and there probably is a diagram on the back showing the condensors)?
- does it come with any negative carriers, lensboards and lenses?
There may be other points that come to mind.
Essentially, most enlargers are quite simple. If you are familiar with them, you can quickly locate most problems. Of course, if you were fully familiar with them, you probably wouldn't need to ask these questions
.
If you have more questions, don't hesitate to either ask them here or pm or email me.
Matt