[jimboombapete]

Diagnostic is to set to M mode with aperture set wide open with a 1s shutter speed, AF off. Observe the lens from the front while pressing the shutter button. If the lens stops down, there is an aperture control problem. Whether it is the aperture control block requires a more intensive diagnostic; fault may be in the camera electronics.


Steve

I've had a chance to do some testing.
Set mode to M, Aperture wide open, 1sec shutter and AF off.
When I pressed the shutter release the aperture closed right down to nothing.

Pete

[stevebrot]

When I pressed the shutter release the aperture closed right down to nothing.

Steve

[perlblau]

Hello from Germany,

after not using my K-50 (bought in Jan. 2014) for about half a year, I tried to take pictures of my son at an (for him) important event last weekend and failed because of the "dark picture problem". Very disappointing, and even more disappointing that it looks like Pentax doesn't provide a working solution (e.g. a new, working solenoid) for its customers.

I've been reading a lot during the last days about what to do and willing to try to repair my K-50 myself, once I find the way to buy the white solenoid at a reasonable price over here in Germany.

Thanks for all your effort in this forum (especially photogem) and all this useful information!

Best regards,

perlblau

[toonpointnine]

Solenoid f Blendensteuerung Pentax K30, K50, K500, KS1, KS2 in Saarbrücken - Saarbrücken-Mitte | Digitalkamera & Zubehör gebraucht kaufen | eBay Kleinanzeigen

I found the above solenoid advertised this week on evil bay (from a google search). Hope I am allowed to post it here.

Good luck

Walter

[Tonistein]

Been using my K500 for almost 3 years without problem. Then started having this dark screen problem. At first I just point at the sky & took some burst shots & it will be ok. Later on that won't work. I got an old lens used on my old Pentax film camera & it work very well with my K500. I read about the dis-assembly of the camera & modifying the solenoid thing. Seems like it's way too difficult for me. I tried a lot of ways & finally came up with this simple thing as shown in the pic.
I remove the lens. At the rear of the lens there's a switch that control the lens opening. Move it up & the lens opening is the biggest. Hold it & insert a small piece of rolled up paper into the groove so that the switch remain in the top position. Put back the lens & the camera works normal again. Been doing that for a year now. So far I did that for 3 lenses - 18-55mm, 10-17mm & 18-135mm. I took thousands of pics this year & my last shutter count was 39,248. Slight problem of over exposure in bright sunlight but very minimal

[photogem]

Solenoid f Blendensteuerung Pentax K30, K50, K500, KS1, KS2 in Saarbrücken - Saarbrücken-Mitte | Digitalkamera & Zubehör gebraucht kaufen | eBay Kleinanzeigen

I found the above solenoid advertised this week on evil bay (from a google search). Hope I am allowed to post it here.

The is not ev... bay but ebay Kleinanzeigen in Germany. One has to register (in German only) to be able to make contact.
Also countries outside the European Union might have to pay VAT and or customs.

I think the quite well known source on ebay.com is the better one for people in USA and Canada and anybody outside EU, even Switzerland!

Or to get them from a damaged *ist/K10D/100/110/K20D/K200D or a K2000/K x/K-r or Samsung GX1/2/10/20

Or MZ5N/6/7/30/60 but those can have opposite polarisation so one has to switch cables for correct plus and minus! (not MZ5, nor 3, different solenoid!)

I tried a lot of ways & finally came up with this simple thing as shown in the pic.
I remove the lens. At the rear of the lens there's a switch that control the lens opening. Move it up & the lens opening is the biggest. Hold it & insert a small piece of rolled up paper into the groove so that the switch remain in the top position. Put back the lens & the camera works normal again. Been doing that for a year now. So far I did that for 3 lenses - 18-55mm, 10-17mm & 18-135mm. I took thousands of pics this year & my last shutter count was 39,248. Slight problem of over exposure in bright sunlight but very minimal

o.k. but now think more about it:

What do you think does happen to the lens? What value of aperture will the camera use to meter?

And what could happen to the aperture mechanism of the camera?


Damn... I just repaired a K50 today and read your post later on, otherwise I would have tried it (with a cheap lens, because if the paper gets inside, the lens can be jammed as well and would need repair)

[Tonistein]

The is not ev... bay but ebay Kleinanzeigen in Germany. One has to register (in German only) to be able to make contact.
Also countries outside the European Union might have to pay VAT and or customs.

I thing the quite well known source on ebay.com is the better one for people in USA and Canada.

Or to get them from a damaged *ist/K10/100/20/200D or a K2000/K x

Or MZ5/6/7 but those can have opposite polarisation so one has to switch cables for correct plus and minus! (not MZ5n, nor 30/60)

---------- Post added 11-21-18 at 04:30 PM ----------



o.k. but now think more about it:

What do you think does happen to the lens? What value of aperture will the camera use to meter?

And what could happen to the aperture mechanism of the camera?


Damn... I just repaired a K50 today and read your post later on, otherwise I would have tried it (with a cheap lens, because if the paper gets inside, the lens can be jammed as well and would need repair)

The paper just to prevent the switch from moving back to original position. It won't jam the lens. I used this method for almost a year

[West Penn]

The is not ev... bay but ebay Kleinanzeigen in Germany. One has to register (in German only) to be able to make contact.
Also countries outside the European Union might have to pay VAT and or customs.

I thing the quite well known source on ebay.com is the better one for people in USA and Canada.

Or to get them from a damaged *ist/K10/100/20/200D or a K2000/K x

Or MZ5/6/7 but those can have opposite polarisation so one has to switch cables for correct plus and minus! (not MZ5n, nor 30/60)

---------- Post added 11-21-18 at 04:30 PM ----------



o.k. but now think more about it:

What do you think does happen to the lens? What value of aperture will the camera use to meter?

And what could happen to the aperture mechanism of the camera?


Damn... I just repaired a K50 today and read your post later on, otherwise I would have tried it (with a cheap lens, because if the paper gets inside, the lens can be jammed as well and would need repair)

Photogem, what specifically is the problem with the solenoid in the MZ5n, MZ30, or MZ60 that is can't be used? Just curious as I have a couple of MZ60's around.

I've got a K-50 with the aperture block failure, but am working around the problem using a manual focus lens with an aperture ring and the green button.

By the way, thanks for all your input on this subject. I'm sure all your comments will come in handy when/if I decide to open the camera and replace the solenoid.

[toonpointnine]

Originally posted by Photogem:

"The is not ev... bay but ebay Kleinanzeigen in Germany. One has to register (in German only) to be able to make contact.
Also countries outside the European Union might have to pay VAT and or customs.

I thing the quite well known source on ebay.com is the better one for people in USA and Canada.

Or to get them from a damaged *ist/K10/100/20/200D or a K2000/K x

Or MZ5/6/7 but those can have opposite polarisation so one has to switch cables for correct plus and minus! (not MZ5n, nor 30/60)"


Hi Photogem,

My post was in response to Perlblau saying he was looking for a white solenoid in Germany.

Like other posters can I thank you for all the advice you have given on this topic (and thanks to the other posters too)? You have inspired me to fix my K50 and I took it apart two days ago (successfully) and am now waiting for a small (15watt) soldering iron to arrive from ebay.

I have had the white solenoid (from USA) since October. That's October 2017!!! I am almost ashamed to admit it! Too frightened to screw up my camera completely by doing it wrong.

The K50 is back-up to my K30 (still going strong, touch wood). Built in February 2015, I bought it used in April 2016, with about 700 shutter actuations. It started to give the odd black frame in June 2017 and failed in September 2017 (every frame black). Approximately 2,800 actuations.

By the way, this week I ordered a blue solenoid as a spare for the future (for the K30), about 15 minutes before I read your comment not to buy a blue one, as the impedance is wrong!

Never mind, when it arrives it will be good for practising my soldering!

Thanks again.

Walter

[photogem]

By the way, this week I ordered a blue solenoid as a spare for the future (for the K30), about 15 minutes before I read your comment not to buy a blue one, as the impedance is wrong!

Never mind, when it arrives it will be good for practising my soldering!

Even if you would find it with the correct impedance:

The blue one is made by the same manufacturer in China as is the green one.

I had several of the blue ones here, 100% made in China

The paper just to prevent the switch from moving back to original position. It won't jam the lens. I used this method for almost a year

Sure, but it will keep your lens in the wide open position only!

If you use a DA35/2,4 it can only meter f2,4 correct, any other values will go wrong. I tried it today, it was sheer disaster.

Also you force the aperture mechanism to work against a blocked diaphragm.

I would have to see about this with an open camera but actually, I don't see any sense in it.
Who wants to shoot always wide open?

Photogem, what specifically is the problem with the solenoid in the MZ5n, MZ30, or MZ60 that is can't be used? Just curious as I have a couple of MZ60's around.

I corrected my post. It is the 5n which is not working, the others can have wrong polarity, not always, but if so, it is a bit time consuming and one has to know that if the camera applies the voltage to such a solenoid with wrong connection the force of the magnetic hold is even stronger instead of a release.
One should check polarisation prior soldering in in with for example 2 x CR2 3V batteries in series so they give you the needed 6Volts.

All this plus the work of dismantling an old body is not worth the work when I can buy a 100% checked and working solenoid.

[reh321]

Been using my K500 for almost 3 years without problem. Then started having this dark screen problem. At first I just point at the sky & took some burst shots & it will be ok. Later on that won't work. I got an old lens used on my old Pentax film camera & it work very well with my K500. I read about the dis-assembly of the camera & modifying the solenoid thing. Seems like it's way too difficult for me. I tried a lot of ways & finally came up with this simple thing as shown in the pic.
I remove the lens. At the rear of the lens there's a switch that control the lens opening. Move it up & the lens opening is the biggest. Hold it & insert a small piece of rolled up paper into the groove so that the switch remain in the top position. Put back the lens & the camera works normal again. Been doing that for a year now. So far I did that for 3 lenses - 18-55mm, 10-17mm & 18-135mm. I took thousands of pics this year & my last shutter count was 39,248. Slight problem of over exposure in bright sunlight but very minimal

A couple of years ago, I did something similar with an AdaptAll lens
Keeping AdaptAll Lens Stopped Down - PentaxForums.com
Not knowing what the complete K-30 mechanism looks like, I didn't know if it would harm the camera's mechanism. If you have used it this way for a year, then I guess it is a way of dealing with the situation for at least the medium range. I wonder if you could do something similar, using two pieces of paper, to jam the mechanism into some value in the middle of the range, although wide-open might be fine for my 18-55mm f/3.5-5.6.

[photogem]

Yesterday (Jan 5th 2019) I tested a Pentax MZ50 solenoid against the version of the K10D.

It's my sons birthday monday and I want to give him my K30. But since a few weeks the pop-up flash would not pop-up anymore. This never bothered me because I hardly ever use flash but for my son I wanted it right.


It was for the first time ever (for me) that a green solenoid failed in the pop-up flash.

I thought I try an MZ50 solenoid and bought a 2.nd had MZ50 very cheap. I unsoldered it and tested it:


It had obvious slightly less holding force than the white versions from the early Pentax DSLR bodies!

And again my sample had opposite polarity.

I installed this white MZ50 solenoid, polarity was zero problem because in the flash circuit the two wires can just be soldered the opposite way.
I was certain all would be alright, I had installed a white solenoid into the aperture mechanism few month ago.

But I had a new hitherto unknown problem:

The pop-up flash would suddenly not close anymore!
The power (holding force) of the solenoid was too weak! The pull on the horseshoe plunger was too strong and kept it in the open position.

Luckily I had a green solenoid from another K30 left over.

So I changed solenoids again, all was fine again.

This made me curious and I exchanged the early white solenoid (from an *istDL2) which I had installed before into this K30
against this white MZ50 solenoid (which included extra fuzzy work for changing polarity of the two wires!):

I had a new problem: Every 2nd or 3rd picture overexposed!

The reason was clearly obvious:
The horseshoe did not move back into its "Locked Position", similar as it did when used for the flash mechanism!

I then moved it manually with the tip of a screwdriver into the lock position, next photo was fine but then again it "stuck wide open".
If I chose the settings for proper speed for wide open, of course all was well.

Same problem using live-view.

I then took another "bad" green solenoid I had and I filed/sanded the anchor until I had similar holding force.
I built this one into the aperture circuit and voila: Same problem!!! This explained to me why so many filed or soldered green solenoids failed.

Changing the solenoids back against the one from the *ist DL2 and all was fine again.


So I recommend to get solenoids only from:

Pentax *ist D, *ist DS, *ist DL, *ist DL2, Samsung GX1/2, GX10/20

Pentax K10D, K20D, K100D, K110D, K200D, Km, Kx, Kr



I came across quite a few of those which had already the green solenoid in the flash circuit!

It seems to me that those green solenoids were only built into EU Pentax bodies because I have heard from several people
now that US, Canadien and Australien early Pentax DLSRs had 2 white solenoids!



I also heard that there is a difference in "Made in Japan" to "Made in Philippines" MZ bodies!?

[K5-0]

I fixed my K50 yesterday with the white solenoid off Ebay (Seller: potmano $45USD+Ship)

Disassembly was fairly straight forward following the videos already on Youtube. Before the operation, make sure you are not lacking patience and have a good quality precision screwdriver set. Take care not to touch the large and obvious capacitor.

Soldering Technique:
1. Using tweezers, gently pull wire while applying hot iron to solenoid lead. The wires should release in a few seconds.
2. Replace green with white solenoid.
3. There should be enough solder left on the wires and white solenoid to make the connection. I applied a very small amount (tip of toothpick) of flux to the leads on the solenoid.
4. Remembering which was pink and purple, touch the wire to the top of the solenoid lead. Hold it there and apply gentle pressure with the hot iron until the connection has fused (you will hear her sizzle).


Very important - During reassembly, make sure the MF/AF switch is toggled in the middle position on the body and functional before you start putting screws back in.


Whole process took less than 100mins.

So I recommend to get solenoids only from:

Pentax *ist D, *ist DS, *ist DL, *ist DL2, Samsung GX1/2, GX10/20

Pentax K10D, K20D, K100D, K110D, K200D, Km, Kx, Kr

Photogem, ^this is a great resource.

Thank you and the Pentax Forum for helping us fix our new, low shutter count K-50s! Less than 7000 shutter actuations on mine.


Fixed just in time for Christmas My guess is that Pentax owners are cat people...

[perlblau]

Yesterday (Jan 5th 2019) I tested a Pentax MZ50 solenoid against the version of the K10D.

(...)

It had obvious slightly less holding force than the white versions from the early Pentax DSLR bodies! And again my sample had opposite polarity.

(...)

The power (holding force) of the solenoid was too weak! The pull on the horseshoe plunger was too strong and kept it in the open position.

(...)

So I recommend to get solenoids only from:

Pentax *ist D, *ist DS, *ist DL, *ist DL2, Samsung GX1/2, GX10/20

Pentax K10D, K20D, K100D, K110D, K200D, Km, Kx, Kr

Thanks a lot for this useful information. Meanwhile I was able to buy a non working MZ50 for only 7€ to take apart for spare-parts. Unfortunately, I would say when reading your recent post.

I don't think it is worth trying, when you already realized that it is very likely that the MZ50-Solenoid is too weak. Damn! So it looks like I will have to buy the 50€-part from Saarbrücken...


Regards

perlblau

[photogem]

Thanks a lot for this useful information. Meanwhile I was able to buy a non working MZ50 for only 7€ to take apart for spare-parts. Unfortunately, I would say when reading your recent post.

I don't think it is worth trying, when you already realized that it is very likely that the MZ50-Solenoid is too weak. Damn! So it looks like I will have to buy the 50€-part from Saarbrücken...

Just make sure you don't buy the green one! There are many offers now on ebay and they tempt people.