[JayDee]

Hey all,

I just made a repair to my K-30 that seems to have worked. Wanted to share my details with everyone.

As best as I can work out, the root of the problem with loss of aperture control is as follows...

The shutter motor also moves the aperture lever. A small encoded gear allows the camera to count F-stops as it moves. Once the right F-Stop is reached, the solenoid is engaged to brake the aperture lever. For whatever reason, the magnetic field created by the coils is not enough to overcome the one in the small magnet on the top of the coil that attracts the armature to it's resting position. This is a purely mechanical problem.


1. Follow the pictures on the Russian Forum to remove the front and bottom covers. Its around 25 screws in total, be sure to label where they go for reassembly. You will have to remove the rubber grips (they seem to stick back on pretty well)

2. To remove the solenoid in question you must remove a single lacquered screw. However the battery compartment is in the way to get inline with it. I drilled a hole in the battery compartment to ensure I didn't strip the head of that screw out. The front cover covers the holes, so water resistance shouldn't be affected. Its better than ruining the screw.

3. Gently pull the solenoid off of its locating pin and remove the small metal U shaped armature from the bottom. It will be fairly sticky to get out, that is, after all the problem.

SIDE NOTE: I don't think the problem is that the armature becomes magnetized. Mine wouldn't even attract metal filings.

4. We want to make this piece less magnetic. I used some 1000 grit sand paper to ease over the edges to reduce the surface area in contact with the magnet. Think how the head of a nail sticks better to a magnet than it's point.

5. Clean the armature with some rubbing alcohol, reinstall, being sure to engage the small knob into the armature and reassemble the covers.

Regarding the flash capacitor- I didn't bother to discharge mine as you don't really need to get near it if you leave the top cover on. If you have a volt meter with insulated alligator leads set it to VDC and walk away for a few hours for it to discharge. OR, use insulated alligator leads and something like a 1000 Ohm resistor (Black, Brown, Red Gold) and it should discharge in about 2 minutes.

I'm going to go out shooting this weekend, I'll power cycle often, change lens and F-stops frequently and see if I can get it to act up again. If it does, I'll sand the armature a little more.

Hope this helps someone!

Attached Images

     

[paolo11]

What do you think that incidence is?

Consumers Union, a non-profit company in the U.S., tests many products and also maintains a database of product reliability drawn from subscriber surveys. Their most recent survey results for interchangeable lens cameras sorts out as follows:

Incidence of Repairs or Serious Problems

• Panasonic: 4%
• Canon: 5%
• Sony: 7%
• Pentax/Ricoh: 7%
• Nikon: 8%
• Olympus: 8%

The results are from 2010-2015, inclusive. Pentax results include the K-5 stain issue as well as the K-3II recall and the K-30/K-50 aperture issues. Consumers Union says that differences less than 5% are not meaningful.


Steve

what I see is missing is the amount of failures per ???

[xunwp]

Hey all,

I just made a repair to my K-30 that seems to have worked. Wanted to share my details with everyone.

As best as I can work out, the root of the problem with loss of aperture control is as follows...

The shutter motor also moves the aperture lever. A small encoded gear allows the camera to count F-stops as it moves. Once the right F-Stop is reached, the solenoid is engaged to brake the aperture lever. For whatever reason, the magnetic field created by the coils is not enough to overcome the one in the small magnet on the top of the coil that attracts the armature to it's resting position. This is a purely mechanical problem.


1. Follow the pictures on the Russian Forum to remove the front and bottom covers. Its around 25 screws in total, be sure to label where they go for reassembly. You will have to remove the rubber grips (they seem to stick back on pretty well)

2. To remove the solenoid in question you must remove a single lacquered screw. However the battery compartment is in the way to get inline with it. I drilled a hole in the battery compartment to ensure I didn't strip the head of that screw out. The front cover covers the holes, so water resistance shouldn't be affected. Its better than ruining the screw.

3. Gently pull the solenoid off of its locating pin and remove the small metal U shaped armature from the bottom. It will be fairly sticky to get out, that is, after all the problem.

SIDE NOTE: I don't think the problem is that the armature becomes magnetized. Mine wouldn't even attract metal filings.

4. We want to make this piece less magnetic. I used some 1000 grit sand paper to ease over the edges to reduce the surface area in contact with the magnet. Think how the head of a nail sticks better to a magnet than it's point.

5. Clean the armature with some rubbing alcohol, reinstall, being sure to engage the small knob into the armature and reassemble the covers.

Regarding the flash capacitor- I didn't bother to discharge mine as you don't really need to get near it if you leave the top cover on. If you have a volt meter with insulated alligator leads set it to VDC and walk away for a few hours for it to discharge. OR, use insulated alligator leads and something like a 1000 Ohm resistor (Black, Brown, Red Gold) and it should discharge in about 2 minutes.

I'm going to go out shooting this weekend, I'll power cycle often, change lens and F-stops frequently and see if I can get it to act up again. If it does, I'll sand the armature a little more.

Hope this helps someone!

This is what I did on the "horse shoe" armature. It works! Cheers!

[paolo11]

yes, i saw that. Were you able to follow what they did with no problem? It seems involved and I'm wondering if i can do this. someone mentioned that a guy in CA repairs this problem for 100.00. For what It's worth, I'm going to go after Pentax.

i can get it working by a rapid fire shooting, then it works. Turn if off for a bit, dark images. This sequence seems to work, but no fix overall.

thanks for your help

[JayDee]

yes, i saw that. Were you able to follow what they did with no problem? It seems involved and I'm wondering if i can do this. someone mentioned that a guy in CA repairs this problem for 100.00. For what It's worth, I'm going to go after Pentax.

i can get it working by a rapid fire shooting, then it works. Turn if off for a bit, dark images. This sequence seems to work, but no fix overall.

thanks for your help

That also worked for me for a while, but it does eventually stop working as a fix.

I've taken about 300 or so shots after my repair and have yet to have this problem show back up.

[JayDee]

This is what I did on the "horse shoe" armature. It works! Cheers!

Wunderbar! Glad this worked for you.

As a note to others, I'm not sure I would remove quite as much material as you did. The old saying- its always easier to remove more material later than to put it back on.

[ERNR]

Another arrangement is to use AA batteries ... there are people who have worked for you. I have not yet had the problem of the diaphragm ... and I only use AA batteries

For the record, I usually use AA batteries and my K30 has experienced the aperture failure.

[xunwp]

Wunderbar! Glad this worked for you.

As a note to others, I'm not sure I would remove quite as much material as you did. The old saying- its always easier to remove more material later than to put it back on.

Yes, you are right.
I had filed a bit and tested the force by trying to pulling it out by hand again and again, before I got this. I know my hand is not accurate...

[paolo11]

For the record, I usually use AA batteries and my K30 has experienced the aperture failure.

I figured as much. I'm going to ship out to CA where a couple of guys will fix the problem for 100.00 plus they pay return shipping and give a warranty, granted, they are a cottage industry and only fix the Pentax aperture problem, but i read good things about them.

[niceshot]

yes, i saw that. Were you able to follow what they did with no problem? It seems involved and I'm wondering if i can do this. someone mentioned that a guy in CA repairs this problem for 100.00. For what It's worth, I'm going to go after Pentax.

i can get it working by a rapid fire shooting, then it works. Turn if off for a bit, dark images. This sequence seems to work, but no fix overall.

thanks for your help

you can handle it

[paolo11]

I mailed it out to be repaired by a guy in CA.

[brunomcf]

Thank you very much for this topic, I just did the repair and my camera is working like on the first day. In Germany they asked me more than 300€ for the repair last year, which made me activate the insurance to buy a K-3 instead of repairing it.

[paolo11]

After looking at a couple of detailed repairs, I should have tried it. Being a former s/w engineer and technician, I'm skeptical as to what degree in filing the horse shoe shaped magnet, would it have worked okay by just taking on/off?

But good luck to all of you for giving it a go.

[HarisF1]

Just removing and replacing it does nothing.

[paolo11]

Which process did you use? Russian or ...

---------- Post added 01-03-17 at 08:58 AM ----------

Thanks