[reh321]

This was made a "sticky" so those who need help and are unfamiliar with this problem would have a place to get started. All this back-and-forth reduces the value of this thread for that purpose.

[Cee Cee]

Really photogem … we are failing to see things the same. All we can do is agree to disagree, shake hands and move on.


sorry, I edited the wording as one of my comments was rude and uncalled for, I apologise.


(Moderator's note: I still felt this was really of no consequence here, and cleaned it up even more. We all need to understand that as a multinational community, there will be times when the true meaning of a comment is lost in the translation. Not to stray from the subject at hand, or take away from the nationalities of those engaged in this misunderstanding, but I read recently that there is no word for the English word love. Yet they have managed to be among the most populated nation in the world. So let's all celebrate our common interests, and try to learn the real meanings when we cross cultural and language boundaries.)

[Cee Cee]

bye the way, just to be clear, about this degaussing business, I recalled reading some where that it I may be that the magnet in the solenoid was too strong and thought at the time if that was the case then the magnet could be degaussed a little and then wondered if this could possibly be done externally with a tape head demagnetiser (which is a much lower powered devise). That would be a nice solution if the camera didn't have to be opened That was as much as I thought about it as My camera hadn't failed as yet and I wasn't expecting it to. When my camera became faulty I began thinking of this again an thought I wonder, having nothing to loose as the solenoid had to be changed anyway I gave it a try, on one attempt I thought it may have made a difference, but it didn't take long to realise this was just nonsense. I didn't even understand the exact nature of the problem, and judging by some of the things I had read I concluded that nobody really did.


finally …. the facts are the facts, the truth is the truth, when people go in different directions in search of the truth eventually they will both arrive at the same place and can go no further, all I'm trying to do is get to the facts, the truth of this problem, I don't have to travel the same road as anybody else, and I don't have to study the works of those that have gone before me.

really gone this time.

[Not a Number]

I recalled reading some where that it I may be that the magnet in the solenoid was too strong and thought at the time if that was the case then the magnet could be degaussed a little and then wondered if this could possibly be done externally with a tape head demagnetiser (which is a much lower powered devise). That would be a nice solution if the camera didn't have to be opened

That's a possibility. The observations are that the magnet on the green solenoids seem to be stronger. Or at least the green solenoids need more force to withdraw the plunger.

The problem I see is that the magnetic field on these tape head de-magnetizers is not very strong. The ones I've used require you to touch the tape head and slowly withdraw the tip so the fields collapse. The other potential problem would be other components that may be affected by the magnet field of the deguasser.

Other options are to increase the magnet field of the electromagnet. Ways to achieve this are:

1. increase power (voltage or current)
2. increase number of coils (wrappings)

or move the magent further away. There is enough room in the slot to move the magnet.

The service manual for one of the "A" model SLRs from the 1980's says to test the operation of the electromagnet by applying 2.0 volts with the proper polarity. It would be interesting to see what the operating voltage is in DSLRs that use the same electromagnet.

Note: with (1) above switching to AA batteries could be increasing the power. It would be interesting to try using one of the AC adapters - mine has a nominal rated output of 8.3v and 2.0 amps.

[Cee Cee]

That's a possibility. The observations are that the magnet on the green solenoids seem to be stronger. Or at least the green solenoids need more force to withdraw the plunger.

The problem I see is that the magnetic field on these tape head de-magnetizers is not very strong. The ones I've used require you to touch the tape head and slowly withdraw the tip so the fields collapse. The other potential problem would be other components that may be affected by the magnet field of the deguasser.

Other options are to increase the magnet field of the electromagnet. Ways to achieve this are:

1. increase power (voltage or current)
2. increase number of coils (wrappings)

or move the magent further away. There is enough room in the slot to move the magnet.

The service manual for one of the "A" model SLRs from the 1980's says to test the operation of the electromagnet by applying 2.0 volts with the proper polarity. It would be interesting to see what the operating voltage is in DSLRs that use the same electromagnet.

Note: with (1) above switching to AA batteries could be increasing the power. It would be interesting to try using one of the AC adapters - mine has a nominal rated output of 8.3v and 2.0 amps.

with the tape head demag I used you can feel it vibrate a little when its acting on a piece of metal, looking at the pictures of an open k30 and trying to position it I could feel some vibration at times, but you are right, at that distance it would be too week to be effective. Besides I no longer think this is the problem, if you reduce the magnetic strength you would also reduce the initial kick when the solenoid is activated, potentially you may get it to work with a different magnetic strength but this would be totally hit & miss, with no way to control the demag process I'd guess a 99.% chance of a miss.

the voltages to run the circuits are internally regulated to provide the correct operating voltage on both battery and external supply. the advantage of running the external supply is that it won't sag under load as a "less than fully charged battery" would.

the recommended test voltage may not be the same as the normal operating voltage

[BigMackCam]

Folks - let's keep all discussion friendly and courteous. We may not agree with each others' ideas, but we can disagree in a constructive way, without calling each other out. Otherwise, infractions and thread bans follow.

Thanks in advance for your co-operation

[MarkJerling]

This was made a "sticky" so those who need help and are unfamiliar with this problem would have a place to get started. All this back-and-forth reduces the value of this thread for that purpose.

As I have recommended before, I really think we need a "general discussion and speculation" thread. I would recommend we rename this one to have that purpose.

Let's start with copy and paste of the facts and only the facts, and as been suggested earlier in the thread, I can then make that a sticky and lock the thread. When more facts come to light, any one of the moderators can, if the members agree, add those new facts to the sticky.

I think that would make it a lot easier for members to navigate around this issue.

Thoughts?

[BigMackCam]

As I have recommended before, I really think we need a "general discussion and speculation" thread. I would recommend we rename this one to have that purpose.

Let's start with copy and paste of the facts and only the facts, and as been suggested earlier in the thread, I can then make that a sticky and lock the thread. When more facts come to light, any one of the moderators can, if the members agree, add those new facts to the sticky.

I think that would make it a lot easier for members to navigate around this issue.

Thoughts?

That's an excellent idea, Mark. Perhaps one or more of our members would like to PM you (if you agree) with a summarised post, or - at least - salient points to include in it?

[MarkJerling]

That's an excellent idea, Mark. Perhaps one or more of our members would like to PM you (if you agree) with a summarised post, or - at least - salient points to include in it?

Thanks Mike.
I think it's good to post here, as everyone can see the suggested content more easily, rather than by PM.

I would suggest that we link directly to the repair solutions, diagnosing the issue, etc. Anyone keen to start? I'd suggest giving your post a title - Aperture issue - Sticky suggestions So as to make it stand out.

[reh321]

Original Post from this thread
I'm not sure we need anything else

[BigMackCam]

Original Post from this thread
I'm not sure we need anything else

So there's nothing from subsequent posts that enriches this? I mean, like stevebrot's immediate reply?

I'm asking because given that Mark has offered to do this, we should consider carefully what we ask him to include...

[Racer X 69]

OK then.

The bickering that happened here over recent hours landed on my lap this morning when I was having morning coffee. I didn't have time to dig in too deeply then, as Mrs. Racer had me doing chores all day, but I see my colleagues stepped in and did some work. One has even suggested a solution.

I like that solution and will support it fully.

Also, I have taken some time and cleaned up some posts. I did my best to leave the facts and experiences as they pertain to this discussion intact. The inane babble that transpired did nothing to support the discussion, and surely led to hard feelings all around, and it is gone.

All parties involved should be ashamed of their behavior. It is the kind of stuff one expects of children on the playground, not grown men. The jabs and insults were disrespectful, to the person directed at, to the other members of this forum, those who come here and lurk, the owners of the forum, and even to the individuals dishing them out.

This is a class joint, and everyone is expected to act respectably, like the adults we all are, and treat each other with dignity and respect.

No matter how much we may disagree or misunderstand each other.

Everybody have a nice day.

Now I gotta go, a race is about to start on the TV.

Don't make me stop the cars!

[Cee Cee]

my thoughts and reasoning are laid out in post #183

in summary,

we know the correct fix, (replace the solenoid) this has been established by others after all this is the way Pentax repairs the camera.

but as to why is this happening ….

I'm of the belief that due to natural variation, age and normal wear & tear, the aperture mechanism reaches a tipping point where the original solenoid can longer correctly function as it was intended or if you like "kick" it into action. Replacing the solenoid with a lower impedance unit provides more "kick" to overcome the reluctance of sytem to operate .

As for why Pentax chose to use a higher impedance solenoid, I can only speculate, but I would think it was to minimise battery consumption, being unable to for see the ramifications further down the line.


there may be cases where other issues with the solenoid come in to play, such as binding of the armature etc but I would think these cases are just a simple case of part failure as can happen, and not the cause of the epidemic of k30/50 failures.

[reh321]

my thoughts and reasoning are laid out in post #183

in summary,

we know the correct fix, (replace the solenoid) this has been established by others after all this is the way Pentax repairs the camera.

but as to why is this happening ….

I'm of the belief that due to natural variation, age and normal wear & tear, the aperture mechanism reaches a tipping point where the original solenoid can longer correctly function as it was intended or if you like "kick" it into action. Replacing the solenoid with a lower impedance unit provides more "kick" to overcome the reluctance of sytem to operate .

As for why Pentax chose to use a higher impedance solenoid, I can only speculate, but I would think it was to minimise battery consumption, being unable to for see the ramifications further down the line.


there may be cases where other issues with the solenoid come in to play, such as binding of the armature etc but I would think these cases are just a simple case of part failure as can happen, and not the cause of the epidemic of k30/50 failures.

I don't think the "sticky" thread should say anything about causes or solutions. That is just asking for trouble.

[reh321]

So there's nothing from subsequent posts that enriches this? I mean, like stevebrot's immediate reply?

I'm asking because given that Mark has offered to do this, we should consider carefully what we ask him to include...

I'm reluctant to include his first sentence. I'm convinced that multiple problems sometimes get lumped in together under this one, and honestly. I don't know whether his first sentence is a case of that or not, The one thing we know is that the photo looks dark but not black.