Originally Web posted Sunday, 5 December 2021.
Content last modified Sunday, 5 December 2021 .
“Tighten the display screws.”
“But they’re already tight!”
“No they’re not, else you wouldn’t be having a problem!”
Does this sort of unproductive discourse seem familiar? If so, maybe this article can help. This article covers Unibody MacBook Pro models, specifically 15" Mid-2012 Non-Retina (MacBookPro9,1) and Mid-2010 (MacBookPro6,2) models, shown in the photographs.
All photos on this page taken with the display clutch cover removed, and in most cases with the display (clamshell) assembly removed from the MacBook Pro base. Here’s a pic of all 12 screws (or screw holes), 6 per side:
The 6 (3 per side) outermost screws whose holes are labeled A in the picture mount the display assembly to the main Mac’s body. Pretty much everyone knows about these. When these are loose, there’s too much free play.
The two visible screw heads and one screw back side (threads) on the actual hinge on each side (total of 6 screws: 4 visible heads + 2 back sides) are the actual hinge screws which affect tightness. I’ve marked the visible heads as B and the back sides as C in the pic.
Here is a looking-down top view then a side view of the C screw heads, with the black plastic display clutch cover removed and bright arrows pointing at the heads, to give a better sense of where they are in the overall layout:
It might look like the C screw is squeezing the hinge more tightly together—it did to me! But then i took the 2 B and 1 C screws out and removed the hinge, and saw this:
There is no second layer to the hinge, anywhere near screw hole level. There is nothing to squeeze. I don’t see any way to adjust hinge tension/friction. I welcome corrections.
Here’s the interesting thing: i tightened the B and (primarily) C screws and my display felt tighter, with less tendency to flop (and it had no free play). Placebo effect?
Start by ensuring that the display mounting brackets (outer ends) are properly seated onto the main body of the MacBook Pro, and that all screws A are completely tight. Consider appropriate thread locking compound if you’ve already had problems with tightening the screws then having them work loose again.
Seems unlikely to me that screws B or C (especially the latter) would cause an excessive free play problem, but if you’re double-dog certain that the brackets are firmly seated and all A screws are tight, check the others for looseness.
Success will almost surely evade you until you remove the display clutch cover. I strongly recommend consulting an Apple service manual or equivalent well-done take-apart documentation with pictures. Brief terse summary with no pictures (yes, you have to do all these things):
Flat side is outside when it comes time to replace the clutch cover.
Tighten screws B and C. The C screws are the ones i didn’t know about until taking the display clutch cover off and truly studying how the hinge works.
It may not be possible to tighten the hinges enough—if indeed the screws affect clutch tightness whatsoever—to get them to behave the way you think they ought. In Apple’s Unibody MacBook Pro service manuals through at least 2010, there is a section entitled Display Hinge Behavior:
MacBook Pro models have a unique counterbalanced clutch system. The design provides a smooth, fluid feel when opening, closing, or positioning the display. The counterbalanced clutch system was designed so that when the display is vertical with respect to the ground, it will remain in place regardless of the angle of the base.
Moving display past vertical allows the hinges to release and the display to close. This is normal behavior and no repair is necessary. For more information, and to watch a video of normal hinge behavior, refer to kBase #HT3304: MacBook Pro: Display hinge behavior.
That knowledge base article appears to have vanished. Original URL was http://support.apple.com/kb/HT3304?viewlocale=en_US, in case you want to go hunting.
The point being: if you’re hoping, as i was, to be able to tighten the display hinge screws such that you can occasionally have your MacBook Pro on your lap when you might be sitting in a relatively high-seated chair such that your thighs slope at approximately a 45° angle and you have the screen open about 100° with respect to the keyboard/trackpad top base surface and have the screen remain in place, that may not happen—by design.
In the case of my Mid-2012 Non-Retina, the display had an annoying tendency to tilt fully open or closed. None of the 12 screws were outright loose. I tightened screws B and especially C until i thought they’d break if i tried to tighten them further. The C pair especially did allow some tightening. It still seems qualitatively to me that the adjustment absolutely did help markedly, even though i find no physical basis for any of the hinge screws adjusting tightness. The only possible explanation i can fathom is tightening the screws sufficiently to distort (bend) the bracket, but given that it fastens to a big, thick, flat hunk of aluminum (the display clamshell frame), this makes no sense either.
At this point i don’t think loosening any screws will do anything other than give unwanted free play, since i see no mechanism for how screw tightness can affect clutch tension. But if i’m wrong, experiment with loosening screws C somewhat. They should remain snug. If that proves insufficient, additionally loosen screws B slightly. Do not loosen screws A.
I’m having trouble imagining too-tight Unibody hinges, but maybe it’s happened to someone, somewhere.