According to Hoosierpopi :
On May 28, 3:38 pm, wrote:

I will greatly appreciate if anyone can guide me in right direction on
this kitchen wall cabinet

With all due respect to those folks who might suggest a solution that
does NOT involve removing the cabinet from the wall and rebuilding it,
that is the only solution worth the effort.

Ditto for those who insist that you can only replace the whole units.
These things are fine for their purpose as long as they're assembled
properly and the parts haven't gotten damaged.

I'm really surprised that the top slid like that. Either it wasn't
glued properly (or at all), or it had no fasteners. All the knockdown
varieties I've seen have fasteners that would prevent this unless the top
completely tore out the fasteners. Which means that this wasn't knockdown,
and was improperly assembled at the factory.

The fact that the top is dadoed also implies it wasn't knockdown - they
don't bother because the fastener systems (usually barrel bolts)
are plenty strong enough. Ikea's aren't dadoed. Nor are HD's. Just
plain butt joints.

Knockdown ones generally aren't glued...

Without removal, you _could_ bash it back into place and use pocket
hole techniques to drill screws from the top into the sides, but
that will likely be unsatisfactory and somewhat unsightly.

You should buy a bottle of
Elmers Woodworking glue (or similar) and have a six or so of clamps
wide enough to clamp sides to side and front to back. Save all the
fasteners you remove when taking the cabinet down - they appeared to
be holding well! Once on the workshop floor or bench, you will be
better able to see what came loose and where glue is needed/could be
effective. The assembly is a typical "knock-down" variety which will
do for years if properly assembled and installed. They do NOT suggest
gluing them up in the installation manuals, but your case seems to be
the exception! I would glue up every joint and remove the backing to
replace it after gluing it up as well.

I'd take them down too.

Pull the displaced nails on the back (so they won't be in the way), but should
be no need to take the back completely off.

Gently ease apart the loose dadoes. If they're not loose, I wouldn't take them
apart.

These look like just the top slid - the cabinet should flex enough to get
the top out (or at least disengaged from the dado so you can get glue in)
without breaking the other joints.

Clean/scrape out any loose crud/glue debris in the dadoes.

Then glue it back in, and use 3 screws (preferably particle board
screws, be careful you get them centered and straight) to tighten each
dado joint _before_ the glue dries - straight in from the outside.
Predrill the holes before gluing.

Put a few screws in the unbroken joints too for insurance. With screws, you
don't need clamps if the dadoes have been cleaned adequately.

You could also use strap clamps instead of bar clamps. Instead of strap
clamps, you could use a "spanish windlass". It's a loop of strap or rope
that you stick a piece of wood through and twist.

You probably could get away with just gluing, but I don't trust glue
on particle board. If you can't bring yourself into having exposed
screw heads and head buttons on the exposed sides, then, you could
not bother screwing that side. Not recommended.

You could get away without gluing because of the screws, but I wouldn't
advise it unless you want to use barrel bolts instead or at least rather
large head screws, and they're tricky and timeconsuming to install properly.

Then nail the loose areas of the back back in place, and reinstall.

As long as the back isn't damaged in the visible portion, no need to
replace. Replacement with exact match is difficult, it'd probably
be easier to replace the whole cabinet.
--
Chris Lewis,

Age and Treachery will Triumph over Youth and Skill
It's not just anyone who gets a Starship Cruiser class named after them.