[Not a Number]

Hope Ricoh use better parts in newer models

Ok, let's see you design, build and market a flawless DSLR.

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Last edited by MarkJerling; 03-07-2018 at 02:25 PM. Reason: Quoted text edited.

[suraswami]

Ok, let's see you design, build and market a flawless DSLR.

They had a good design, going cheap on the part is the problem, especially when Pentax market share is so thin can't afford to make these mistakes. Pentax has the reputation of building Cameras that lasts, want to see they fix this issue.

Yeah my comment was not nice but that comes from a True Pentax fan and hasn't ditched the brand.

K2000 still going strong 7 yrs.

Proud owner of K2000, Kr, K50, K3 and one point and shoot with zoom film camera.

[photogem]

... One difference I have notices is that magnet used in DVD drive solenoid is slightly (1mm) higher than the one in the camera but all external/important dimensions were the same.

You have not used the proper "made in Japan" white Solenoid, but a DVD drive solenoid which also has a slight off impedance.
This could couse damage in the future.

..... Put new solenoid in its place and solder the wires to it. I have put both covers temporarily back on and tested camera. It was not working any better. After some deliberation I flipped little magnet in solenoid upside down. And camera spring back to life. I have make about hundred test photos since. All well exposed

One has to measure polarity of the two coils, this is an induction magnet similar like very early loudspeakers where constructed, they had no permanent magnets but fieldcoil magnets. Those two coils induce an opposite magnetic field. Your DVD solenoid would have to be soldered with the wires exchanged so that polarity is correct.

Internal resistance (measured using cheap Chinese multi-meter) of both parts :
- Original green Pentax solenoid: 14 ohm
- DVD ripped solenoid: 26 ohm

Strange: every green solenoid I have measured had about 30 ohms!
I only used white solenoids with 30 ohms (29-31 ohms).

Btw. I do not recommend soldering wires midway as this is actually more difficult to do and involves way more solder and heat.

If one is a beginner in soldering

YAY!! fixed it. I learned how to Solder too

better not to make such silly statements!

If one presolderes the thin wires and then solderes them parallel (first pull a tiny piece of shrinking-tube over one side of each of the two wires) there is no excessive solder and heat. For those unexperienced maybe a saver way. The extra thickness of the two wires with the added shrinking-tubes does not interfere.

Soldering station available from German shop starting with 'L' won't do as it doesn't have right tip.

Nonsense:The two German producers are Weller and Ersa. Both have exchangeable tips.
The right tip is the tip one choses.

Soldering irons available in diy shop do not allow for temperature control and don't have right tip.

There are of course soldering irons with temperature control such as the Ersa PTC70, not that I would buy it, one can get a whole Ersa
soldering station for that price.

But the small 15W Ersa can use the finest tiny tips and will not be too hot:
https://www.amazon.com/ersa-Universal-Soldering-chisel-shaped/dp/B01KTVNAT2/...words=Ersa+15w

This is the one I use when I visit others:
amazon.com: Multitip 15W/910BD ERSA: Appliances?tag=pentaxforums-20&

and this is the best soldering station for me:
ersa RDS 80 electronically temperature-controlled soldering station, 80 W, 115 V - - amazon.com?tag=pentaxforums-20&

With all Ersa soldering irons, one can use the finest pencil-tip tips:
https://www.amazon.com/ersa-soldering-0832SDLF-lead-free-extended/dp/B00LW45...+soldering+tip

but I can solder the wires very well with the standard 2.2mm tip, but.... I know how to solder.

If one does not really have any real experience, recommendations like yours can and will mislead others!

One should only recommend things if one knows (by experience and not the nilly-willy content in one's head!)

Another critical recommendation of yours:

I have removed bottom and front cover from my camera and located faulty solenoid (as per instruction from first page. No need to remove top cover).

The top cover is not completly removed, because it still has some cables connected to the main electronics.
One lifts the top cover for easier access to solder the solenoid.

[niceshot]

Nice wright up, good job. thx

[Kevin B123]

Thanks to the valuable information in this thread, I have just fixed my K-50 at 20,000 clicks (Manufactured 21 Sept 2013).
I took the solenoid from a non working for spares K110 that I bought for £4 .

I tried a DVD solenoid, it did not work for me. That one measuerd 15 ohms and I soldered the leads to the solenoid pins. That is difficult since the pin is only about 0.7mm diameter and maybe 2mm long. There is a high risk of melting the plastic and contaminating the joint. That may have happened with my attempt, I can't be certain as I could not view the joint under a magnifier - or least I did not try.

I took MarkJerling's excellent suggestion earlier in this thread and soldered an in line splice, both the solenoid flying leads and camera leads were stripped back, fluxed, pre-tinned and held together for the moment when the soldering iron touched them. This is much easier I think that trying to joint to the solenoid. I used insulating tape to cover each joint and tacked them into the body with a small dob of silicone adhesive. The K110 solenoids were of course, white and 30 ohms.

Please do watch out for that capacitor, It's genuinely dangerous!

[suraswami]

Thanks the the valuable information in this thread, I have just fixed my K-50 at 20,000 clicks (Manufactured 21 Sept 2013).
I took the solenoid from a non working for spareS K110 that I bought for £4 .

I tried a DVD solenoid, it did not work for me. That one measuerd 15 ohms and I soldered the leads to the solenoid pins. That is difficult since the pin is only about 0.7mm diameter and maybe 2mm long. There is a high risk of melting the plastic and contaminating the joint. That may have happened with my attempt, I can't be certain as I could not view the joint under a magnifier - or least I did not try.

I took MarkJerling's excellent suggestion earlier in this thread and soldered an in line splice, both the solenoid flying leads and camera leads were stripped back, fluxed, pre-tinned and held together for the moment when the soldering iron touched them. This is much easier I think that trying to joint to the solenoid. I used insulating tape to cover each joint and tacked them into the body with a small dob of silicone adhesive. The K110 solenoids were of course, white and 30 ohms.

Please do watch out for that capacitor, It's genuinely dangerous!

So the one that went bad on the K50 is also a white one?

[Kevin B123]

No, The original bad one was green (30 ohms), the DVD one that I tried and did not work for me was white and 15 ohms, the K110 replacement that works fine is white and 30 ohms.

In the picture I posted, both white ones were from the K110, one aperture and one for the flash pop up.

[photogem]

Yes, I tried as well a few DVD Solenoids, white and blue, all had 15 ohms and did not work.

[bigyinn]

Just a heads up for those that need a white solenoid, the MZ-7 also has two white solenoids. One for releasing the flash and one for the aperture block. The flash release one is easier to get at, although you do have to remove the top plate. The one for the aperture block is attached to a ribbon cable rather than individual wires and is harder to remove.

[photogem]

Just a heads up for those that need a white solenoid, the MZ-7 also has two white solenoids. One for releasing the flash and one for the aperture block. The flash release one is easier to get at, although you do have to remove the top plate. The one for the aperture block is attached to a ribbon cable rather than individual wires and is harder to remove.

I checked 2 solenoids from a MZ-7 (see photo):

The solenoid for the flash (the one one the right foto with black marking) had opposite polarisation!

Both solenoids have a stronger magnets than those I found in the K10D.
I did not measure the holding force but it is very clear when you pull the horseshoe.

[bigyinn]

I checked 2 solenoids from a MZ-7 (see photo):

The solenoid for the flash (the one one the right foto with black marking) had opposite polarisation!

Both solenoids have a stronger magnets than those I found in the K10D.
I did not measure the holding force but it is very clear when you pull the horseshoe.

So the flash release solenoid will not work correctly if used in he K50? I assume the other (on the left) would be ok to replace the green solenoid found in the K50?

[photogem]

So the flash release solenoid will not work correctly if used in he K50? I assume the other (on the left) would be ok to replace the green solenoid found in the K50?

The polarisation is not a great problem, one just could solder the cables differently. Possibly at the other end, not on the side of the solenoid itself because here the cables are too short, lengthening would not be such a good idea.

What worries me more is the higher release force needed.

I applied now 6 Volts from two CR2 batteries, then I can release the horseshoe quite well, but for the white solenoid of a K-x or a K10D I need just
one CR2 battery to have almost the same loss of holding force.

I have a K30 here to repair and I run out of white solenoids.

So just an hour ago I opened a K200D as I thought, fine, I will replace the white flash solenoid inside the K200D's with the green one of the K30.
Bad surprise: The K200D has the green solenoid installed (see photo). The aperature solenoid is the white one but I will not touch this, the K200D
is working well. Luckily there is a source in Germany where I can buy the white solenoid, a bit dear but those never let me down.

I have found green solenoids in
K100D, K-m (K-2000), K-x, K-r and K200D!
I once had luck with a K200D (silver), it had both solenoids in white..... so I thought I give it a try. Too bad!

[danielblues]

Luckily there is a source in Germany where I can buy the white solenoid

Can you post this source? Thank you.

[photogem]

Can you post this source? Thank you.

pm sent

[MarkJerling]

pm sent

Would you mind posting the source here for everyone to see?