[clackers]

Not if the solenoid was not bad (no aperture control block failure, the case being addressed by my statement).

But when the solenoid is replaced, the problem is fixed. Not any other materials or part, just the solenoid, Steve. You're an IT guy too, this is a controlled variable, right?

I know you also spent a great deal of effort suggesting the K-70 did not seem affected by the problem! You were saying reports were few and ambiguous. I never understood, I must admit. Do you still stand by that?

---

Last edited by clackers; 09-21-2020 at 09:14 PM.

[SharkyCA]

But when the solenoid is replaced, the problem is fixed. Not any other materials or part, just the solenoid, Steve. You're an IT guy too, this is a controlled variable, right?

I know you also spent a great deal of effort suggesting the K-70 did not seem affected by the problem! I never understood, I must admit. Do you still stand by that?

When mine was repaired for "dark images" they replaced the whole "control block" !

[revelstoked]

Huh??
K-30, K-50, etc bodies are most usable with old Pentax lenses, such as the FA lens I personally use with my K-30.
When I purchased this lens in the Marketplace here, the money went to another PF member.

yeah, sure. That is what I have been doing for years with my K50 but I have not bought one new lens from Pentax (despite really wanting the 20-40) because none of them have a manual aperture control. How many people with a failed aperture block are going to buy a new Pentax lens they can't use?

[reh321]

When mine was repaired for "dark images" they replaced the whole "control block" !

but when people follow the DIY instructions provided by photogem, they replace only the solenoid.

[reh321]

yeah, sure. That is what I have been doing for years with my K50 but I have not bought one new lens from Pentax (despite really wanting the 20-40) because none of them have a manual aperture control. How many people with a failed aperture block are going to buy a new Pentax lens they can't use?

They add to the market for used lenses, putting cash in the hands of the sellers who often buy the new lenses.

[revelstoked]

They add to the market for used lenses, enabling the sellers to buy the new lenses.

haha.. Touche!

[clackers]

When mine was repaired for "dark images" they replaced the whole "control block" !

Well, there *is* a new solenoid inside it. Do you feel ripped off, Sharky?

[clackers]

yeah, sure. That is what I have been doing for years with my K50 but I have not bought one new lens from Pentax (despite really wanting the 20-40) because none of them have a manual aperture control. How many people with a failed aperture block are going to buy a new Pentax lens they can't use?

?

Just fix it, Revelstoked, or get it fixed yourself.

There was a Danish guy in the marketplace selling the white solenoids for 12 Euros.

He also does the repairs himself but since you're in different countries it's probably not worth it.

[stevebrot]

But when the solenoid is replaced, the problem is fixed. Not any other materials or part, just the solenoid, Steve. You're an IT guy too, this is a controlled variable, right?

There is no question that swapping out the solenoid usually resolves the problem. There is also the occasional failure (two recently) where the camera behaved rather strangely afterwards, but those may have been due to poor wire/solder work. Reports of recurrence after the repair are probably not reliable either.

I know you also spent a great deal of effort suggesting the K-70 did not seem affected by the problem! I never understood, I must admit. Do you still stand by that?

Not exactly...There was the rare report some time ago of possible aperture block failure on the K-70 and knowing that there are other potential causes for dark exposures (e.g. bad metering)**, I set up a reportage thread where we could qualify the claims and track what fixes were actually done for warranty work. Detecting aperture control failure is pretty easy. Assigning cause is a little more difficult. Replacement of the aperture block from an authorized repair facility is clear indication that some aspect of that assembly was suspect or had failed. There was never any question about whether we would see replacement of aperture control blocks. The big question was the frequency over time. During the period I was maintaining the thread, all of the cameras with confirmed aperture control failure that were serviced had the control block replaced. Whether all of those could have been fixed with a simple solenoid replacement is unknown as is the color and source or origin of the solenoids on both the original and the replacement components.

Since then, there have been user repairs of K-70s using a replacement solenoid with good results. I think that speaks adequately.

The rarity of the problem on the K-70 and to a lesser extent on the K-S2 may be taken as indication that changes had been made. What those might have been are speculative and what role the "resistor chip" being included in some recent service center repairs might have played is hard to say.


Steve

[PocketPixels]

You miss the entire problem here. The solenoids don't "fail" - they simply work in a different way, and the mechanism which assumes they will work in a particular way ceases to work correctly.

If a sandwich counter sells $5 tuna subs all day long, and if 3% of those tuna subs have hairballs in them, which of these solutions would satisfy you?

• a) Don't worry; that guy on the park bench will remove the hairball for just $1
• b) You miss the entire problem, here: the tuna doesn't have the hairball; the mayonnaise has the hairball
• c) Don't worry; there are numerous, easy-to-follow videos on YouTube for how to remove the hairball yourself
• d) Just get back in line and buy a fresh tuna sub; 97% of the replacement tuna subs are hairball-free
• e) That's what you get for ordering the $5 tuna sub; none of the more expensive sandwiches at this place have hairballs
• f) Hey, everything fails from time to time; you've never had a flat tire on your car?
• g) The hairball isn't really a problem if you stifle your gag reflex and use old-school condiments from the 1980s
• h) Let's have everyone post photos of their gross sandwiches on Instagram until the owners of this sandwich shop change how they make sandwiches

You're solidly in the b camp. That's okay; there are multiple valid answers, here (I guess?) But I'm team h all the way.

[clackers]

The rarity of the problem on the K-70 was a indication that changes had been made. What those might have been might explain what happened on the K-30/K-50 bodies. Solenoids such as those that have been failing are ubiquitous in many common devices and if a major supplier was providing junk, the fallout would have been much broader than a single model of Pentax cameras. That is why when one of the K-70 repairs in Europe included replacement of something called a "resistor chip", bells went off. Apparently the current fix at Precision also involves that part.

Okay, but K-70 owners are swapping over just the solenoid, not the rest of the aperture block, not some resistor chip, and their cameras work again.

A Danish Pentaxian thanked Photogem just a couple of weeks ago ...

Tutorial/Repair Pentax K-70 with aperture-problem: Exchange solenoid - Page 3 - PentaxForums.com

[stevebrot]

Okay, but K-70 owners are swapping over just the solenoid, not the rest of the aperture block, not some resistor chip, and their cameras work again.

Tires are bald...replace tires! (Cause: bad ball joint)


Steve

[clackers]

Tires are bald...replace tires! (Cause: bad ball joint)


Steve

Then the white solenoid fixes wouldn't hold up, if it was something else. Many people have done this repair now.

It's been proven with a multimeter that the green solenoid has different properties to the white one.

You'd have to show that the aperture blocks of the cameras that failed were somehow different, to prove your bad ball joint theory.

We talked about controlling variables. The aperture block has remained basically of the same design until the K-70, where Photogem claims it was tweaked to better cope with the green solenoid.

[revelstoked]

?

Just fix it, Revelstoked, or get it fixed yourself.

There was a Danish guy in the marketplace selling the white solenoids for 12 Euros.

He also does the repairs himself but since you're in different countries it's probably not worth it.

Why would I do that? My K50 is old now and well used. Mine failed just outside of warranty and, lucky for me, I didn't have the money back then for new lenses so I had some nice old Asahi glass. Out of necessity I learned to shoot full manual, which I quite enjoy now. All my lenses, save 2 very dusty kit lenses, have manual aperture control. I might spend some money whenever K-new finally materializes, if it makes sense for me. Then I may finally get that 20-40 I keep thinking about and Pentax will get some of my money again.

[clackers]

Why would I do that?

That's totally up to you, Revelsoked, but others have repaired their camera or simply bought a replacement, rather than be in manual aperture all the time, and not use lenses that don't have the ring.

It was you who said you were missing out on the DA20-40 Ltd, not me!

I have it, and it's great.