Minolta 9000: Examination of the sticky shutter and discussing solutions

Following these threads on issues with the Minolta 9000


I am starting a separate topic on the common problem „sticky shutter“ to look at the issue in detail and discuss solutions.

I follow here @ogtronix who has already discribed and solved this problem by removing the shutter unit, see
Post in thread 'Minolta (Maxxum) 9000: Dissection and investigating the aperture issue'
https://www.photrio.com/forum/threa...gating-the-aperture-issue.208476/post-2850057

For this I have further examined a 9000 that has already been disassembled, without having to take into account later reassembly.

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The infamous sticky shutter on the Minolta 9000

A common issue with the Minolta/Maxxum/Alpha 9000 is stuck shutter blades, similar to what can occur with the Canon T90:


This affects the operation of the shutter curtains, leading to incorrect exposure of the images or even complete failure.

Let’s look at the shutter of the 9000 in detail:





Removing the shutter unit from the back.

To do this, screws on the front of the unit and on the back must be loosened. I also unscrewed a lever on the mechanism on the bottom so that the unit could be removed.

The wiring has already been destructively cut with side cutters. If a repair is required, the cables must be desoldered.




Here you can see the shutter unit from the rear and the front shutter curtain.

The two arrows point to material that is sticky and can be found in traces on the rear shutter curtain, which is folded under the bottom frame of the shutter unit.












Further disassembly.










The reason for the sticky contamination is clearly visible: a damper in the lower part of the shutter unit that has decomposed over the decades.




Here you can see the sticky dirt on the rear shutter curtain.

The remains of the damper are sticky, but the consistency is viscous. This means that the damper can be easily removed in this state with the pointed probe.

I am assisted by the friendly Sparefroh, a figure who is popular with savers in Austria


Cleaning attempts on the rear shutter curtain, which can also be done with the camera assembled

To do this, the shutter must be cocked so that the rear shutter curtain is pulled up.




For cleaning with cleaning sticks I use isopropyl alcohol, Zippo lighter fluid and acetone in order and at different places.




Isopropyl alcohol …




… Zippo lighter fluid …




… and acetone.

Of course, you shouldn't use plastic cleaning sticks with acetone, like I do here …




Zippo lighter fluid on cleaning sticks worked best, but isopropyl alcohol and acetone also did the job.

Since there is no plastic in this part of the shutter and the shutter unit is mounted on a die-cast alloy, the sparing use of acetone should be safe.




Sticky dirt can also be seen on the front of the rear shutter curtain, which is accessible when the shutter is cocked and the mirror is lifted.

Alternatively, I would try putting one drop of Zippo lighter fluid directly on the shutter curtain. This should spread the Zippo with a few shutter releases and at least neutralize the stickiness.

But the lighter fluid should not act directly on the rotting damper so as not to liquefy it, which would aggravate the problem.

The front shutter curtain can be accessed when the shutter is released (from the back and from the front, with the mirror raised).




The current consistency of the damper: viscous and sticky, but not liquid.




Fine springs are hooked onto the closing curtains.




Unfortunately, you only have this much control when cleaning the shutter when it is removed.

Possible solutions for the sticky shutter problem

I see two ways:

1. Clean the rear shutter curtain (and if needed the front shutter curtain) from the outside as described. This is a temporary measure that needs to be repeated but does not solve the cause of the problem.
2. Dismantling the shutter unit, disassembly, removing the rotting damper, installing replacement, reassembling. To do this, the mirror box must be removed. @ogtronix shows this solution here: Post in thread 'Minolta (Maxxum) 9000: Dissection and investigating the aperture issue'https://www.photrio.com/forum/threa...gating-the-aperture-issue.208476/post-2850057

Conclusion

• The cause of the sticky shutter, which can lead to malfunctions or failure of the shutter, is a rotting damper. This damper sticks to the rear shutter curtain in particular.
• Cleaning the rear shutter curtain from the outside can be attempted with the shutter cocked using isopropyl alcohol, Zippo lighter fluid or acetone. The front shutter curtain can be treated in the same way with the shutter released. To reach the front side of both shutter curtains lift the mirror up. This measure only works temporarily and does not solve the underlying problem.
• The long-term solution is to remove the shutter, clean it and fit a replacement for the damper as @ogtronix has shown. To do this, the mirror box of the 9000 has to be dismantled, which is a complex and time-consuming process. Minolta expressly advises against in the service manual, as it requires adjustments that only Minolta could carry out with the appropriate measuring devices:

Practice will show how you can progress with these two methods.

I will try cleaning from the outside and report here:



Maybe after completing his repair project @ogtronix would like to report whether the 9000 works properly after cleaning the shutter and reassembling it. That would be very interesting!

As always in DIY, it remains exciting


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All information provided without guarantee and use at your own risk.

I made some corrections, this should be the final version

I'd need to figure out a real shutter tester to really test my shutter at high speeds, but it seems to plausibly work. I shot a roll and a half of film which turned out fine outside of the aperture failing for some shots. Although one of those rolls was Ilford XP2 so even with the aperture being off the shots look fine. Weird film! They're all photos of family over the holidays so i'd be hesitant to post any.

ogtronix said:

I'd need to figure out a real shutter tester to really test my shutter at high speeds, but it seems to plausibly work. I shot a roll and a half of film which turned out fine outside of the aperture failing for some shots. Although one of those rolls was Ilford XP2 so even with the aperture being off the shots look fine. Weird film! They're all photos of family over the holidays so i'd be hesitant to post any.

Click to expand...

Great!

This motivates me to try to take another 9000 apart to clean the shutter!


Regarding shutter tester:

Given the vagaries of disassembling this complex camera to clean the shutter, I'm thinking of alternatives.

Since the damper is sticky but largely retains its shape, I wonder if it could be chemically stabilized without damaging the shutter? By introducing an appropriate liquid chemical from the outside.

Too bold an idea?

I did spend a bit daydreaming about maybe injecting and then sucking back up bits of solvent with a bent styringe with a bit of sponge on the tip through the film gate to gradually dissolve them out, like a housefly. But that'd probably not work and just risk flushing sticky residues and solvents further into the camera.

I forget if you said, but do all your bodies have the same sticky shutter problem? I feel i'd never heard of it happening to the 9000AF till recently (could be wrong, im forgetful), or noticed that both the bodies I have have it. Wondering if it's something that only starts to show up when you use the bodies long enough to start noticeably transferring the slime to the shutter blades, or if it's only recently that they've started breaking down to the gooey stage. It's just kinda funny that it seems to be becoming a bigger reason to disassemble these things than the classic aperture problem.

ogtronix said:

I did spend a bit daydreaming about maybe injecting and then sucking back up bits of solvent with a bent styringe with a bit of sponge on the tip through the film gate to gradually dissolve them out, like a housefly. But that'd probably not work and just risk flushing sticky residues and solvents further into the camera.

I forget if you said, but do all your bodies have the same sticky shutter problem? I feel i'd never heard of it happening to the 9000AF till recently (could be wrong, im forgetful), or noticed that both the bodies I have have it. Wondering if it's something that only starts to show up when you use the bodies long enough to start noticeably transferring the slime to the shutter blades, or if it's only recently that they've started breaking down to the gooey stage. It's just kinda funny that it seems to be becoming a bigger reason to disassemble these things than the classic aperture problem.

Click to expand...

I assume that all my 9000 (9 - 5 out of order) are affected. Some show no abnormalities, but the damper as part of the shutter was probably built in as standard.

The stuff gets definitely onto the shutter curtain when the camera is in use.

As with the T90, only there you can easily remove it from the outside, at least the part that is causing problems.

It's a shame it affects these too. I was into Canon DSLRs years ago and had a few EF lenses, but the Canon SLRs I looked at all had the shutter slime problems. That along with the lens DRM (there's a microswitch in the earlier bodies that detect if a lens is attached, and if the lens isn't officially canon chip recognized it refuses to release the shutter) made me look at the alternatives.