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Forum: Pentax K-3 & K-3 II
10-14-2020, 04:18 PM
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You're welcome, mine still working after cleaning.
BTW I used same cleaning also for Omron microswitches in my MS optical mouse that started to make random doubleclicks instead of singleclick. Can be disassembled quite easily.
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Forum: Pentax K-3 & K-3 II
02-16-2020, 08:04 PM
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Compressed air - no way...
I had to follow the Belarussian guy disassemble video to remove top cover. The switch itself is well covered so nothing can be done without getting in. I had to disassemble the tiny switch and observed that the metal membrane was a bit oxidized on inner side. It looks like a silver (a bit cheaper), definitely not gold that should stay innert. So I cleaned the membrane surface and contacts in the switch body and put it back together. Now my shutter-release actuate sensitive and accurate as before the problem started so I hape it will last long. There seems not be any replacement switch on ebay/aliexpress... If someone else will have this problem I warn that the switch and it's internals are very tiny, sharp vision, tiny tweezers and still hands needed...
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Forum: Pentax K-3 & K-3 II
01-31-2020, 11:30 AM
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No no, I take care about that. In a case of corrosion I would expect that it will not be sensitive on direction how button is pushed but it would have a constant problem.
I found one video where AF button is replaced -
You Tube
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src="https://www.youtube.com/embed/GKK5cpdpPE4?controls=1" allowfullscreen>
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on 1:51 I can see the shutter release button but not in a close detail. I have to browse my photos of disassembled K-30 and compare if the switch could be the same...
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Forum: Pentax K-3 & K-3 II
01-31-2020, 09:15 AM
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Hm, maybe but K-3 body should be well sealed and I didn't take it near to sea. How did you solved it? Just did some cleaning? Of course I should try it first but I have bad experiences with other mechanical switches that simply wear out and the contact resistance will rise that more pressure have to be applied until it loose contact at all. On other hand I have no any problems with shutter release button on all my prev. cams including cheap compacts...
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Forum: Pentax K-3 & K-3 II
01-31-2020, 07:24 AM
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Hi,
I use K-3 for about 3 years (I upgraded from K-30 after some aperture solenoid and shutter problems) and now I started to having problem with shutter release button. When I do half-press to focus it always start focusing but when I do full press to take a shot then sometimes nothing happen (focus locked OK) like the 2nd contact in the button didn't switch on full press. As a workaroud it works when I press the button by finger not in the middle but close to back edge (side to me) then It always take a shot on full press.
It's not a serious problem but I'm a bit disappointed that Pentax used some crappy switch in top model camera (I expected it should be built more robust than K-30). Does someone else have this problem on K-3? My cam is now out of warranty. Does anybody know if the switch is the same (or have compatible dimensions and contacts) as in K-30 so I could replace it?
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Forum: Pentax K-30 & K-50
04-19-2019, 06:48 PM
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Solenoid plunger must be clicking and moving during shot. If not it may be mechanically blocked or no driving current passed through it (maybe blown transistor switching the coil). Here is voltage pulse I measured on coil during shot. You can chek it via scope.
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Forum: Pentax K-30 & K-50
03-18-2019, 02:54 AM
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In my case the problem appeared before I assembled it - I was testing it with inserted battery and removed front and bottom cover. My cam was lying disassembled in desk drawer for ~2 years until I fully assembled it now, so this is a different case...
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Forum: Troubleshooting and Beginner Help
03-17-2019, 06:54 PM
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I cannot longer edit my older post #133 so I don't reccomend to use this paper hack (use on your own risk when you don't have any other choice on a phototrip) instead replace the faulty solenoid.
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Forum: Pentax K-30 & K-50
03-17-2019, 06:26 PM
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Ajax156, interesting info that I'm not alone with this problem (maybe not the same, my cam FW doesn't freeze) but unfortunatelly we still don't know the cause. It's positive, that at least in your case, the issue was temporal. Just to be sure, your mirror problem started just after you replaced the solenoid and has gone when you opened and assembled it again?
Please can you make a simple test:
1) with unmounted lens turn on the cam in bulb mode
2) press and hold the shutter
3) after the mirrot lifts and aperture lever moves up try gently pull the lever down with a tweezer on small screwdriver, stop pull when you feel some resistance
How it moves? In my case I can pull it very softly down to default position (one half), when i release the lever it moves up via som spring, not much fast.
Just want to see if it behave same or differently.
BTW didn't you used this quick hack: https://www.pentaxforums.com/forums/attachments/58-troubleshooting-beginner-...-objektivu.jpg before repair? If it may have some coincidence with mirror problem...
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Forum: Pentax K-30 & K-50
03-14-2019, 05:56 AM
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How can you claim this? You neither I knows what happened inside the mirror box. I didn't applied any excessive force/violence to front cover when removing it. Even if so it shouldn't damage gears deeply inside mirror box but may cause e.g. problem wit AF switch but it is working fine, I have aligned it properly.
My problem may be caused by using the camera for cca a half year with manually blocked lens aperture level by a piece of paper (a hotfix for constant ~f/8 https://www.pentaxforums.com/forums/attachments/58-troubleshooting-beginner-...-objektivu.jpg) while still operating weared out solenoid...
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Forum: Pentax K-30 & K-50
03-13-2019, 09:23 PM
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Yes, discharging a HV cap is generaly a good idea (I was kicked by some flash cap of a compact camera years ago so I know :) but as you read before it can go wrong when done improperly...
I don't remember exactly, maybe I just released a bit some screw of top cover to be able to remove front cover but didn't need to fully remove it and didn't need any extra force or wiggle. I have a fine solder tip so no problem with space when soldering. Let users decides if they could work more comfortable with top cover removed...
Yes sure, AF/MF switch needs proper aligment in all cases.
I did sanding method before and found that I sanded it too much so holding force was too weak that in some case the anchor didn't return back to sticked position. I ended up buying a new cheap (inferior) green solenoid that moves anchor correctly. I no longer get underexposed images but mirror movement is still some way random and I cannot figure out why. I think something else broke/weared out and even if I use white solenoid it will not fix this issue. The cam had done over 35000 shots and now keeping it just as a backup body (and maybe for some firmware hack fun where don't care much if gets bricked).
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Forum: Pentax K-30 & K-50
03-11-2019, 05:17 PM
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I didn't feel a need to discharge the flash capacitor in K-30 as I didn't need to remove top cover for solenoid replacement. It seems someone did much worse because too much effort instead if he simply leave it charged...
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Forum: Pentax K-30 & K-50
03-06-2019, 08:57 PM
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According this picture mirror always up, shutter stays closed, and camera operates slowly - PentaxForums.com
by twey user it seems to be correct. In basic position the lever is in the middle and the spring is hidden. When pres the shutter in bulb mode the lever moves up (to the right on photo) and the end of spring will jump out from bottom. There is smaller secondary plastic lever linked with main lever that moves together that is below the spring. I suspected if it shouldn be above spring end but twey photo says not.
The problem is that lever movement goest 2 different way when shutter is pressed that changes randomly by my observation.
1) simple movement when lever goes directly from center position up (relatively slowly) and the mirror goes up, when shutter released it returns back to center position
2) more complex movement when it seems the lever quickly goes up then immediately back to center and then immediately up again. Also the mirror flips twice. Spring jumps the same way. After release it moves back to center. In a rare case (happened one time during maybe 200 shots it just tried) the mirror get stucked partially flipped and I have to turn off/on.
You Tube
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src="https://www.youtube.com/embed/TJ3aiqtzILA?controls=1" allowfullscreen>
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All I did I replaced the sanded solenoid with cheap green one from ebay. I sanded it too much and it had too weak holding power. New green one holds much more tight. When lens is mounted the plunger moves correctly.
I didn't get any underexposured image so for me it's OK to be usable as backup body...
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Forum: Pentax K-30 & K-50
03-05-2019, 08:54 PM
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BTW Did you knew our Czechoslovak tube manufacturer TESLA (nothing linked to Elon Musk :)? They was making pretty good tubes, best in eastern Europe. It was distributed to other countries. Same tubes models was also made in Poland (Polam, Telam) and imported here, they was cheaper but worse. Currently AFAIK Tesla is making only some special RF power tubes for narrow customers. But in Slovakia there was revived the tube manufacturing under brand JJ Electronic - Company profile I think their quality is also good, they sell most of production outside, AFAIK also as OEM for Mullard...
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Forum: Pentax K-30 & K-50
01-25-2019, 07:57 PM
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Oh, it's bad but still not a 100% proof that it was caused by sanding and didn't fail for other reason/wear out. Probably it depens on a camera load if someone would use it only as a backup body it may be OK as there are people using their sanded cams for an year or more...
Well, sometime's I'll have a look on ebay for older bodies, currently there's no offer of suitable dead body. As I collected info this models should contain white one: *ist, K-10D, K-x, K-m, K2000, K100D, K110D, K200D
Yes netto, but when I include the shipping and import tax it rise to 72$.
What about this one? New Genuine Repair part For Pentax K30 K50 KS1 KS2 K500 K 30 K 50 K S1 K S2 K 500 DSLR digital camera Aperture Solenoid Plunger-in Camera Flex Cables from Consumer Electronics on Aliexpress.com | Alibaba Group
Yes, there are thousand of posts about this theme and unfortunatelly noone wrote a sumary article. It cannot be read within a hour or a week but I'm reading through....
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Forum: Pentax K-30 & K-50
01-18-2019, 07:52 PM
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Oh, so you mean that bad solenoid can cause permanent damage during time to other mentioned components? One couldn't belive it. Are there such users who got problem back after grinding and when they replaced by good solenoid their cam still didn't work because other parts died too? Wasn't it just a coincidence?
BTW is the white solenoid available cheaper somewhere else than Pentax K-30 K-50 K-S1/S2 K-500 Genuine Aperture Solenoid Plunger Part - Japan - | eBay ? There is only one offer on ebay, others tens of offer are all green (and who knows if not recycled ones). White one is quite expansive ~ 60$ is 1/3 of used K-30 body... Pentax surely get it for a few $ from the manufacturer. I can see that other people rip it off older cams...
BTW I found interesting page about solenoid testing. It shows that solenoid is driven only by a short pulse that in some case collapse to a short glitch that is not sufficent to actuate. I though that drive pulse is much longer. He also measured release force in this mode showing that green solenoid needs 4x greater force than white...
Captain Bodgit: Fixing my Pentax K-30 exposure problem: #4 more details on solenoid |
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Forum: Pentax K-30 & K-50
01-16-2019, 10:17 PM
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Hm, "nice" so they treat EU as inferion country where the can sell a crap?
How can I determine the target from camera body markings or S/N? I can only say my K-30 is "PENTAX RICOH IMAGING CO., LTD, Assembled in Philippines" I saw that some K-30 has Pentax mark on LCD and other has Ricoh so it might changed during the production (and also the solenoids)...
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Forum: Pentax K-30 & K-50
01-16-2019, 08:55 PM
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>photogem
Sorry, I just found and read your clarification post #653 and now got better understanding and I appreciate your investigation and effort on your various kind of solenoids analysis. But there's near a thousand of posts that one cannot read all in a reasonabe time (and I'm busy with gathering infos about my SDM issue).
I think it's a pity there's not possible to stick/link such interesting/solution posts on top of 1st page so one can quickly see and jump there. Even worse there are more than one aperutre thread on this forum and more on other forums...
I'm just not sure about yout last claim that "The mirror flopping issue develops as a result of using the the sanding" - people who did this reported it works for them several months but I didn't investigated further. In my case I had probably some problem with spring on lever/mirror mechanism so the problem started immediatelly after my disassemble if I remember well. I still have my partially disassemled K-30 body lying in a cabinet but my motivation to continue with repair is low as didn't find any mech.drawing or detailed photos that would help me to put it right way and I have more urgent repairs and jobs to do...
Is there some explanation how this solenoid have a connection to mirror flipping mechanism?
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Forum: Pentax K-30 & K-50
01-14-2019, 02:56 PM
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I think too so I give a warning about different resistance.
You can order from ebay by an item photo from but you cannot be sure what they really sell.
Anyway I don't longer care myself. I repaired it by grinding original metal armature
http://rayer.g6.cz/hardware/pentax.k30/soleno3.jpg
and it worked fine again but I had mirror flipping problem instead so I rather upgraded to K-3 that works well and I like it but now stucked with dead SDM in my favorite lens, sigh...
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Forum: Pentax SLR Lens Discussion
01-13-2019, 02:21 PM
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Forum: Pentax K-30 & K-50
01-13-2019, 02:12 PM
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BTW I extracted one similar solenoid from a notebook DVD drive:
http://rayer.g6.cz/hardware/pentax.k30/soleno4.jpg
But as I measured the coil DC resistance it was only 16,6 ohm while K-30 coild has 29 ohm. So I wouldn't use it as it may damage some transistor switching the coil due to overcurrent (If I assume that it is powered directly from battery 8,4V the current could reach 0,5A).
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Forum: Pentax DSLR Discussion
01-11-2019, 08:53 PM
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Thank you for the link, I had to register.
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Forum: Pentax DSLR Discussion
01-07-2019, 09:22 PM
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Hi, please do you have a link for lens EE dumps?
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Forum: Pentax DSLR Discussion
01-06-2019, 11:27 PM
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I disassembled my DA 17-70mm f/4 AL [IF] SDM lens that have damaged SDM also to check if there is an EEPROM chip. I carefully looked at all chips but there is not common serial EEPROM. There is TI MSP430F1232 16-bit MCU with embedded 8,25 kB flashROM. So it may hold lens data inside. So it would not be such easy to read/write it as serial EEPROM.
Here is photo of the PCB
http://rayer.g6.cz/hardware/pentax.k30/da1770c.jpg
I'd also ask for help technical skilled users who own the same lens DA 17-70mm f/4 AL [IF] SDM to help me identify the value of blown resistor
(pointed by arrow) on bottom side of PCB.
http://rayer.g6.cz/hardware/pentax.k30/da1770d.jpg
It's not hard to disassemble (~10min) and there are step by step instructions
The chip list (most of them are tiny SMD parts with a short code hard to be identified. The big NEC chip seems to be something custom, google's silent):
top side:
TI M430F1232 17TG4 (TSSOP28, 16-bit MCU 8kB+256B FlashROM, 256B RAM, 10-bit ADC)
MF1 405 (micro SOT23-5)
bottom side:
B1AV (SOT23-5, near motor pins)
2* fairchild BHAA WZ08 (micro TSSOP8)
fairchild PB0AA LCX74 (DQFN14, 7474 dual D-type positive edge-triggered flip-flop 3,3V)
Z86F (micro SOT23-5)
Z16B (micro SOT23-5)
5W55 (micro TSSOP8)
5W56 (micro TSSOP8)
T6E5 (SOT23-5)
162Y (SOT23-5)
lens body FPC:
NEC LIC092 118M1 (TQFP48)
58C 171 (TSSOP8)
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Forum: Pentax SLR Lens Discussion
01-06-2019, 11:11 PM
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