PowerBook 1400 Hinge Repair

[AwkwardPotato]

I've been looking over the display in my new 1400c and have been researching some possible ways to fix it. Here's what I've found so far:

- Hinges are attached to the back display bezel via 3 brass standoffs just like the infamous ones found in the PB 100 series

- For each hinge, there is one standoff in the curved part of the bottom of the bezel, and two right under the LCD panel, which are covered by a part of the metal backing

- Both of the standoffs in the curved part had completely disintegrated on my unit. Parts of metal backing covering other standoffs had detached due to metal fatigue, remaining standoffs look undamaged

- Huge cracks in the back of the bezel (of course), might attempt plastic welding or may just use epoxy

- Each hinge has only one small clutch, which has an exposed area that looks *just* wide enough to apply some lubricant and work it into the hinge

These are just some preliminary notes for now; I'm going to hold off on repairing it until I have an appropriate lubricant. Any suggestions?

 

[Trash80toHP_Mini]

Lubricant's a good idea if it's stiff. Have you checked the ServiceSource?

Fatigue cracking at the back of the lid near the hinges is more common than I'd like. Good lid plastics would be the limiting factor in my 1400 stack. A few are seemingly perfect, some not so bad and some in pretty bad shape, but not as bad as Beater's.

Very bad cracks on my original, badly beat up 1400c still remain, bad enough I leave it open on display, only closing and opening it rarely and very carefully. Not sure I want the pretty new stuff installed on it. I tried solvent welding to no avail years back, so I started bottom feeding eBay for parts donors and deals. I've got a plastic welder, but haven't tried it on thin lid plastics. doesn't seem the thing to do, at least with the Harbor Freight rig on hand.

I've dabbled at laying up glass cloth with a thick ABS/ABS cement slurry to reinforce failing plastics and adding just the slurry itself for an unrelated project. No definitive results to report, but haven't found a reason to stop playing around with it time, weather and interest providing. Thought I'd mention it if you'd like to play around with the process if you have extra parts for experimentation. Shade tree fiberglass reinforcement/FRP/whatever might be a way to go, but I've yet to check clearances in the 1400 lid.

Good luck.

 

[AwkwardPotato]

After seeing the thickness of the cracked area, I definitely don't want to attempt plastic welding on this part either. I think I'm going to mess around with some pieces of a mutilated 6100 case to try and find what would work best. Regarding the brass inserts, would ABS cement be better than epoxy for reattaching them to the case?

 

[Trash80toHP_Mini]

No, that's only for ABS-to-ABS solvent welding. They use ABS rather than PVC for plumbing in mobile homes, campers and such. Post some pictures of what's going on in your situation. I haven't opened up the lids of my 1400s yet to have a look.

 

[AwkwardPotato]

Here's a photo of the back bezel's 3 brass inserts I was talking about (bottom one destroyed). The hinge crack common to PB1400's can be seen directly above the inserts.

 

[AwkwardPotato]

Right now I'm trying to decide which lubricant to buy for use on the hinges -- I'm avoiding WD-40 at all costs since it contains petroleum products (will wreak havoc on the plastic), and the two that I've found so far that are (supposedly) least likely to harm the plastic are silicone grease and white lithium grease. Any ideas for which one would be better?

 

[AwkwardPotato]

Update: I did a bit of searching on these forums and found reports that you cannot use adhesives on materials that have come into contact with silicone grease (could render the bezel unrepairable if the other standoffs broke). Going to try the lithium grease on the hinges instead.

 

[beachycove]

I’d probably go with a tube of Goop/ ShooGoo/ other brand names that all seem about the same thing. The tube is large, and contains a clear viscous liquid that dries somewhat flexible, but with an astonishing holding power. It would do for both the crack and the brass thingie. I’d let it dry for a week or so before reassembly, and I’d also overfill slightly to maximize surface contact.

Recently, the leg broke off my daughter’s glasses at the metal hinge. They were irreparable. New glasses had to be ordered, which involved waiting for an appointment, etc., so while waiting, I glued the leg back to the frame with this stuff, in a simple butt joint. The joint was made in just a tiny physical area, but Goop held that pair of broken glasses on her head, with them being removed and adjusted and so on, for a week or more until her new glasses were available, and then they made it home in her handbag, still holding together. There’s no way that an epoxy adhesive could have withstood the flexing and held in the same way.

 

[Trash80toHP_Mini]

.  .  .  you cannot use adhesives on materials that have come into contact with silicone grease (could render the bezel unrepairable if the other standoffs broke). Going to try the lithium grease on the hinges instead.

Do not lubricate anything until after you've finished with your plastic repairs. Epoxy is the thing to use for the brass insert. Make sure to rough up the surrounding plastic to give the epoxy something to bite into. Epoxy is wonderful stuff because you can drill/tap and machine it. Goop is great stuff where you want the flexibility, but I don't think that's what you want for the brass insert.

WD-40 is not a lubricant, you won't find that word anywhere on the can of the original Water Displacement-40. It's used as a cleaning agent because it's mostly volatiles that flash off, leaving little residue behind, that's its design purpose. Now it's a brand name for all kinds of lubricants, but the classic stuff doesn't fall into that category.

 

[OleLila]

So if I used classic brand name WD-40 thinking I had used a lubricant...it has likely evaporated now? I used it on an old PC laptop with sticky hinges and it sure acts that way. If so..here comes silicone.

 

[just.in.time]

@AwkwardPotato

After you make all the plastic repairs, I’ll throw my vote in for White Lithium Grease. WD-40 (the company, not product) sells a can of it and the description on the back seems to describe your metal on metal hinge situation pretty well as a use case. Best of luck!  

 

[AwkwardPotato]

Well, I scored, roughed up, and cleaned the plastic per the instructions for the epoxy I used. Unfortunately after applying the epoxy and leaving it to cure for over 48 hours (even though it's advertised as being able to cure in 1 hour), the cracks I repaired broke again when I barely (and I mean barely) applied some force to the joint with my fingers  :/ . I was even able to remove it all with ease using a dull x-acto knife. Are there any other epoxies that have proven successful for PowerBook repair?

 

[Unknown_K]

I use this for a lubricant, it does not dry out or evaporate:

 

[just.in.time]

...Unfortunately after applying the epoxy and leaving it to cure for over 48 hours (even though it's advertised as being able to cure in 1 hour), the cracks I repaired broke again when I barely (and I mean barely) applied some force to the joint with my fingers  :/ ...

That is unfortunate.  I had a similar experience helping a friend repair an HP laptop back in college.  And that was on a 3 year old laptop with "fresh" plastics.  Hinges, especially with single areas of contact at each end, exert a lot of force at that area when being opened or closed.  After several attempts at repair (including a couple types of epoxy), our end solution was to drill two bolts through the rear lid plastic and add some flat metal to both the inside and outside to squeeze onto the lid's plastic.  It was so far from pretty, but worked.  Probably not the response you are hoping for :/

Do you have a hot-air rework station?  I wonder if you could melt the plastic enough to reseat the broken piece of metal and to "reflow" the plastic in the cracked area to become one again.  I've never tried this, anyone else here with plastics experience think this could be a solution?

 

[AwkwardPotato]

Having to drill through the plastic really wouldn't be the end of the world, especially since this machine was pretty much a basket case to begin with (dead battery, dead hard drive, dead CD-ROM, dead trackpad, beat-up plastics, no AC adapter, and a couple of bulging caps on the logic board).

I do own a cheap hot air station, but I'm worried that using it to fix the shattered standoffs and cracks would end up in the plastic being deformed/warped (the 1400 plastics are *really* thin).

 

[just.in.time]

If the plastic is already beat up and you don't mind bolts punching through the backside of the lid, then it is definitely a solid fix.  If you want I can try to dig up photos of the HP unit to show you what we did.

I didn't realize how thin that plastic is, good call on skipping the heat in that case.

 

[AwkwardPotato]

Update:

I got around to working on this machine again. The epoxy I linked to above does work for the standoffs, but not the cracks in the back panel. I'm assuming this is because there's so little surface area to bond inside the crack in the back panel, and I'm going to look into other methods of repairing the cracks soon. I also tried using silicone spray on the hinges, and they certainly feel smoother (could be placebo effect though and granted I haven't worked on this computer in ~2 months).