The latch that opens my G4 Quicksilver takes a lot of force before the door will open. I worry it is about to break because of the force I need to apply. Is there anything I can lubricate so it operates with less force needed? Operating the lever seems to make a large clear panel slide, and much of this panel is under the logic board. I'm not really sure where the extra friction is coming from.
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Latch to open G4 Quicksilver is sticking, feels like it is going to break
- Thread starter cplum
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You are not wrong in your concern.
The way that Apple designed the "spring" for the latch, was to make it (the latch mechanism) attach to the rest of an inside plate via several slender pieces of plastic.
Over time, those slender pieces develop fractures as the plastic ages and degrades. There is nothing that can be done about that. Buying NOS is probably just a stopgap option, since the plastic has aged, even if it hasn't been flexed.
Most people simply buy a used case of the correct type, and solve the problem (put it off for another day/owner) that way.
The best thing would be for one of the following two options to happen:
1.) Fair option: reproduce the complete assembly (might include making available a hinge replacement at the bottom as well). Do not know if it could be printed, or if, to make it last longer, it would need to be molded (would still need a replacement hinge).
2.) Best option, redesign the door assembly so that the necessary "latch spring assembly" is replaced by actual metal springs, not plastic, plus an easy to install replacement bottom door hinge. In a case like that you would have the option to print the door and any non-stressed items (and provide an easy to replace hinge pin for the door), and install metal springs (coil or leaf or some other type) to provide the required return action to hold the latch in place.
The way that Apple designed the "spring" for the latch, was to make it (the latch mechanism) attach to the rest of an inside plate via several slender pieces of plastic.
Over time, those slender pieces develop fractures as the plastic ages and degrades. There is nothing that can be done about that. Buying NOS is probably just a stopgap option, since the plastic has aged, even if it hasn't been flexed.
Most people simply buy a used case of the correct type, and solve the problem (put it off for another day/owner) that way.
The best thing would be for one of the following two options to happen:
1.) Fair option: reproduce the complete assembly (might include making available a hinge replacement at the bottom as well). Do not know if it could be printed, or if, to make it last longer, it would need to be molded (would still need a replacement hinge).
2.) Best option, redesign the door assembly so that the necessary "latch spring assembly" is replaced by actual metal springs, not plastic, plus an easy to install replacement bottom door hinge. In a case like that you would have the option to print the door and any non-stressed items (and provide an easy to replace hinge pin for the door), and install metal springs (coil or leaf or some other type) to provide the required return action to hold the latch in place.
If the latch handle breaks, how do you open the case? Seems like that would be difficult. I was thinking maybe I should pre-emptively break off all the internal latches that keep the door closed and then just keep it closed with duct tape.
Another thought was to introduce flat springs to assist the latch with sliding the panel. They would always be putting some force on the panel to move it into the open position, but not so much that it would actually move it (much). Then when you operate the external latch it would not require as much force to open. Here are a couple of flat springs that could probably be repurposed for this:
Here's a picture that hopefully conveys what I'm suggesting (I would use more than just the one flat spring shown).
Another thought was to introduce flat springs to assist the latch with sliding the panel. They would always be putting some force on the panel to move it into the open position, but not so much that it would actually move it (much). Then when you operate the external latch it would not require as much force to open. Here are a couple of flat springs that could probably be repurposed for this:
Prime-Line PL 7758 Screen Tension Spring in Flat Steel, 3-1/8 In. (6 Pack)
These are heat-treated steel tension springs hold window screens into sliding aluminum window screen channels. Requires (2) 3/16 inch holes drilled 3-3/16 inch apart.
www.amazon.com
YHXiXi 50pcs Spring Clips Stainless Steel Picture Frame Hardware DIY Picture Framing Tools 85x9mm
Artwork, back panel, cross stitch, etc. Easy to install. Made of high-quality stainless steel, durable and long-lasting. Suitable for pictures and picture frames and mirrors. Slide between the support plate and the rear rail of the frame so that the picture is tightly facing the front of th...
www.amazon.com
Here's a picture that hopefully conveys what I'm suggesting (I would use more than just the one flat spring shown).
As an Amazon Associate, MacRumors earns a commission from qualifying purchases made through links in this post.
I had already tried that and it didn't seem to help, at least not much. I have two of these G4 Quicksilvers. With the door open, if I push on the tabs to make the panel slide, it is easy and smooth on one of them, and hard and squeaky on the one I'm complaining about here. Maybe I should lift the logic board and see if I can find something to lubricate, or maybe snip some of the plastic that acts as a spring.
Reason I suggested that is my DA has the same issue. The plastic latches deform over time, and heat cycles.
I removed the lock mechanism from my DA because it seemed to be part of the problem, and felt it was useless in my case. Since I was in there doing airflow mods anyway I just made it go away.
I removed the lock mechanism from my DA because it seemed to be part of the problem, and felt it was useless in my case. Since I was in there doing airflow mods anyway I just made it go away.
The "spring" that holds the latch in place are small strips of plastic that go from the main piece of plastic inside the door, to a smaller rectangle that is attached to the actual latch itself. The small strips are used as "springs".
Over time, the plastic ages and crystallizes, or rather the complex carbon chains break down. The plastic gets brittle - with or without use - and at some point fractures, leaving the small strips broken at one end or the other (usually, since those are the locations of maximum strain).
So, ultimately, even if you were to get a NOS (which by now is at least 21 to 27 years old) door, it could very easily break simply due to age.
That is a design "flaw" in that body style. I would be very surprised if anyone on the original design team ever imagined that we would still be using what they built, "that long ago".
Even back then, even with Apple products, 3 years was old, and 12 or more years is an "eternity". No one in high technology builds with that in mind. And definitely not for 20+ years. The body plastic on my 7100's is quite brittle.
My main G4 has the door held in place with tape. I took the insides of the door apart (took off the motherboard, and very carefully unthreaded some of the harnesses that go under it and found the problem). The latch plate (the plate with the latch mechanism molded integrally into it) can be replaced.
But in order to get the latch plate assembly out, you have to strain those small plastic strips beyond what is necessary to simply unlatch it, and in the process of getting the latch plate assembly out, the strips will often break.
If a dealer has one in good shape they might be willing to sell the whole door assembly. However, the pin that goes through the bottom edge is bradded over at both ends. They would rather sell the entire body with nothing in it.
In order to get the hinge pin out, you must first grind off a brad, very carefully, and remove the hinge pin. And then, replace the door, insert a new hinge pin, and very carefully brad over the new hinge pin.
That's why I suggested that someone needs to redesign the door assembly, with a new (probably) set of metal springs and build the doors for sale.
Over time, the plastic ages and crystallizes, or rather the complex carbon chains break down. The plastic gets brittle - with or without use - and at some point fractures, leaving the small strips broken at one end or the other (usually, since those are the locations of maximum strain).
So, ultimately, even if you were to get a NOS (which by now is at least 21 to 27 years old) door, it could very easily break simply due to age.
That is a design "flaw" in that body style. I would be very surprised if anyone on the original design team ever imagined that we would still be using what they built, "that long ago".
Even back then, even with Apple products, 3 years was old, and 12 or more years is an "eternity". No one in high technology builds with that in mind. And definitely not for 20+ years. The body plastic on my 7100's is quite brittle.
My main G4 has the door held in place with tape. I took the insides of the door apart (took off the motherboard, and very carefully unthreaded some of the harnesses that go under it and found the problem). The latch plate (the plate with the latch mechanism molded integrally into it) can be replaced.
But in order to get the latch plate assembly out, you have to strain those small plastic strips beyond what is necessary to simply unlatch it, and in the process of getting the latch plate assembly out, the strips will often break.
If a dealer has one in good shape they might be willing to sell the whole door assembly. However, the pin that goes through the bottom edge is bradded over at both ends. They would rather sell the entire body with nothing in it.
In order to get the hinge pin out, you must first grind off a brad, very carefully, and remove the hinge pin. And then, replace the door, insert a new hinge pin, and very carefully brad over the new hinge pin.
That's why I suggested that someone needs to redesign the door assembly, with a new (probably) set of metal springs and build the doors for sale.
My first QS - the triangular latch end parts broke off mine which I glued back together but then broke off again. The lock latch is the mechanism how I keep the door closed.
I have many G4 powermacs and this QS is the only unit where a sticky door latch has occurred. For any friction points, you could go in between those rubbing surfaces with a lubricant around the logic board. Also as spoken to above, this doesn’t fix the aging/degradation of the plastics but could reduce the wear on some of those friction points. Another thought is the door may be misaligned and sticks slightly (usually at a top corner). I have a MDD that is like this ever so slightly- has been that way since day one when I picked it up. The tolerances on these cases are not as precise compared to the tight tolerances of a powermac G5 or cMP. Here’s a vid of how the pmG4 door latch works.
I have many G4 powermacs and this QS is the only unit where a sticky door latch has occurred. For any friction points, you could go in between those rubbing surfaces with a lubricant around the logic board. Also as spoken to above, this doesn’t fix the aging/degradation of the plastics but could reduce the wear on some of those friction points. Another thought is the door may be misaligned and sticks slightly (usually at a top corner). I have a MDD that is like this ever so slightly- has been that way since day one when I picked it up. The tolerances on these cases are not as precise compared to the tight tolerances of a powermac G5 or cMP. Here’s a vid of how the pmG4 door latch works.
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Problem solved. I decided to remove the logic board to see what the spring panel looked like, and try to find where it might be rubbing. Didn't see or find anything unusual, but I did clean up the dust and jiggle things around a lot. I also unscrewed the panel to see if I could just remove it, but it was hung up in one corner, and I didn't feel like removing the part that it was snagging on, so I started the process of putting everything back together. At each step I kept closing the door and re-opening it, and found it was working great. When I was done putting it back together, sprayed a bit of silicon spray on the latch, and now it seems better than new. Barely any effort at all is needed to operate the latch.
My guess is it was hung up on something (maybe the modem wire), and I inadvertently fixed it with the disassembly and reassembly. I'm just glad to not have to worry about breaking the latch now.
My guess is it was hung up on something (maybe the modem wire), and I inadvertently fixed it with the disassembly and reassembly. I'm just glad to not have to worry about breaking the latch now.
Well done! The modem wire does go under the board and can get caught.
I will just have to buy a salvaged case, or continue to use duct tape. Sigh . . .
I will just have to buy a salvaged case, or continue to use duct tape. Sigh . . .