We just got some cabinets from IKEA to hang above my wife’s sewing area. Here are the stats:
Do I…
From the weight I’m guessing that the cabinets are wide, long, and/or a bit of both. You’ll need to, not only, locate the wall studs, but make sure you find the center of each stud. You’ll install 1"X3" horizantal hanging braces and then the cabinets. Here’s a tutorial video for kitchen cabs. that should help: http://www.easy2diy.com/cm/easy/diy_ht_3d_index.asp?page_id=35750421
Not familiar with IKEA cabinet construction. Is there a horizontal strip inside at the top which could be predrilled to match the centers of your vertical framing? If not, then you could premount a hanger as suggested. BTW-never use drywall screws to mount cabinets. The shanks are thin, and being hardened, are also brittle. Better to predrill holes and install full shank flat or oval headed wood screws, either counterbored to sit flush, or install with cup washers.
Former professional cabinet installer here.
This is probably what I would do. Run a bead of construction adhesive (like liquid nails) along a 1 x 4, and then put it up on the wall, screwing into each stud. Then just screw the cabinets onto that.
Or, if the cabinets have solid backs and you feel pretty confident in your stud-finding abilitities, you can just screw directly through the cabinet backs into the studs. Be sure to use shims if the back isn’t flush to the wall.
Here’s a pic of the cabinets, by the way.
They’re square, but made of heavy particle board.
The mounting holes (reinforced with metal brackets) are circled in orange in my photo.
The holes are 20in. apart.
The back panel is NOT structurally significant on its own (w/o the brackets)—1/8" masonite, attached with tacks.
One really secure method is to fix a chamfered batten to the back of the cabinet, then another to the wall and hook one onto the other.
Like this - You fix the timber to the back of the cabinet with the chamfer facing down and inwards, and the one to the wall with the chamfer facing up and inwards (the plain batten on the bottom of the cabinet is to stand it off the wall and keep it all level.
These can be long battens running the entire length of the cabinet back. The more you load the cabinet, the tighter it pulls into the wall. The headboard end of my son’s cabin bed is fixed to a stud and plasterboard wall in exactly this way.
After dropping the cabinet into place like this, a couple of screws can be driven through from the inside, into wall-mounted batten - to lock the whole lot in place if there’s any risk of it being accidentally lifted off its mounting.
I can’t see (in your link) how sturdy the factory mounting is. You might use a 1X3 inside the cabinet, screwing through it into the wall studs. You want to use heavy, long wood screws to go well into the studs. Again, make sure you screw into the center of the studs.
I meant to add that the significant advantages with the batten method I described above are that there’s no mucking about trying to hold something heavy in place while screwing it to the wall, and no fuss at all in getting the mountings aligned.
I’d have to recommend against this method. It’s a fantastic technique if you’re hanging nice sturdy cabinets, but these Ikea models, with due respect, look like cheap crap.
You wouldn’t be able to attach the batten directly to the back of these Ikea cabinets. You’d have to screw them in so that the weight is pulling on the screws longitudinally (make sense?), and melamine is a lousy material for this.
You might be able to pull it off if you first attached a cleat on the inside of the cabinet (by screwing through the sides), and then attached a batten to that by screwing through the back. But if you’re installing a cleat like that, you might as well just screw it directly to the studs.
ETA:
Good point. If you’ve got no help in putting them up (I never had this problem), Mangetout’s method might be a lifesaver.
I agree - fixing the batten to cabinets where no substantial material exists to screw into could be a big problem with this method. If the cabinets have reinforced anchor points, you’re going to have to work with those.
If you think you might move out of the property before the cabinets wear out, and you don’t want to take them with you, you could plaster the back of the entire cabinet with No More Nails, press it into place and hold it there with props and sprung sticks until the glue dries, then walk away laughing maniacally. Just be sure to get it in the right place, and level.
My brother was hanging similar cabinets. I suggested he mount a rail on the wall to rest the bases of the cabinets on and then use brackets to hold the backs to the wall.
Has worked well for several years.
I hope this is a whoosh. The backing of the cabinet is thin masonite stapled to the cabinet. It’s only real function is to keep it square.
It is kind of hard to see how the mounting points interact with the rest of the cabiet.
I would get a 1x3 or just a piece of molding and cut it to length for the inside top of the cabinet. Glue it in place and screw through the molding and cabinet backing into studs. Provided the cabinets have enough integrity to hold themselves together.
Your not putting these above the head board of your bed I hope. 
Or, you could put molding outside on the wall at the bottom of the cabinet. Let the cabinet rest on that. Of course you still will need to secure the cabinet to the wall.
