DL wrote:

I've got a couple of IBM 3151 terminals that are getting dim and out
of focus. I want to open the case to see if there are any internal
brightness/focus pots that can be adjusted. (I am aware that internal
voltages can be hazardous and will take precautions.) However, I
can't figure out how to get the case back off as there are no screws.
Can anyone give me instructions?

Thanks,
Dan
If these units are like some other IBM monitors, they have narrow slots
that allow access to the latch? You need a narrow piece of metal with
a taper to a point on one of the straight edges. My recollection is
that the metal strip is about 1/8" wide, 3/8" high, and needs to be
about 6" long. (the slot dimensions in the cover will confirm your
width and height) The taper should be to a point at one corner of the
strip at one of the flat edges, and taper back on the strip about 1 1/2
inches. Once you have such a tool made, you place the flat edge of the
strip UP and insert it into the slot with the tapered edge down.
Pushing forward on the strip releases the latch.

You can try a pointed item like an ice pick or awl, but they do not
work as well as the tool described above if your latch is the same. Of
course once you remove the cover, it will become all too evident what it
needs. Then again, your cover might have some other type of latching
system. I just thought I would share this info with you in case your
cover worked the same way.