|
Forum: Pentax K-30 & K-50
07-09-2017, 06:40 PM
|
| |
Yes, that is the part actually works, bought several and no problems at all. Original Japanese part.
|
|
Forum: Pentax K-30 & K-50
03-07-2017, 05:49 PM
|
| |
Entry level cameras use solenoids to stop the opto-coupling aperture gear generally.
K-7, K-5, K-3 and K-1 series use a very robust stepper motor which is rated for 100.000.000 actuations.
Even Nikon D810 uses a similar but smaller solenoid which brakes often to cause mirror stuck in open position.
What we learn here is, solenoids for critical SLR mechanisms are not ideal unless they are really high quality made.
|
|
Forum: Pentax K-30 & K-50
02-11-2017, 11:27 PM
|
| |
As I read all the posts since my last post, all I see here is lots of vague conversations... do not take personally, I am sorry to tell you the truth.
Take my word who is in the repair business for a long time and worked with Japanese teams designing cameras.
The culprit is the new CHINESE MADE plunger solenoid. It is out of voltage specs and it MUST be replaced with a quality Japanese product such as Panasonic, Alps or Mitsumi made.
Filing the part is quite laughable especially when you need to reopen your camera when it fails in a short while.
Mirror box, Shutter and main board has NOTHING to do with that.
Nikon, Canon, Olympus and Minolta has similar mechanism utilizing the same solenoid in a different location due to patent issues.
Nikon D3 and D4 has been upgraded to step motor control due to a different shaped solenoid failure which controls the aperture and it causes the 'Err' message on the early prototypes (which was very common in D2H)
Canon does the aperture in the lens to prevent the same issue.
Replace the part if you can find it and be all set. Pentax is a well engineered brand and has nothing less than the others.
|
|
Forum: Pentax K-30 & K-50
11-28-2016, 05:57 AM
|
| |
You may send it to me for a permanent, fair and honest repair if you wish.
|
|
Forum: Pentax K-30 & K-50
11-22-2016, 11:48 PM
|
| |
| |
|
Forum: Pentax K-30 & K-50
11-09-2016, 06:06 AM
|
| |
Please ignore the shaving thing, it is not the real solution since that method decreases the magnetic grip of the solenoid. You need to get the part as mentioned, and YES even if it is a walkman originated solenoid it will last at least 100.000 actuations.
|
|
Forum: Pentax K-30 & K-50
10-16-2016, 08:52 AM
|
| |
Two... any SLR with electronic flash release button has two. (K-5, K-7 and K-30's flashes are mechanical release so there is no solenoid)
|
|
Forum: Pentax K-30 & K-50
10-15-2016, 10:28 PM
|
| |
For sure *ist, K-X, K-R, K10D models have two useful identical solenoids, one for the flash pop up up and the other for the aperture control. I have not checked any film SLRs but they (which were produced since 90's) are very likely to use the same part.
|
|
Forum: Pentax K-30 & K-50
10-15-2016, 08:56 AM
|
| |
I would first verify to get momentary voltage to the solenoid, camera body should send the power at a fraction of a second. In some cases, the solenoid coil becomes defective and could not demagnetize against the permanent magnet.
Then your best bet is old walkmans which use logic touch drive instead of direct mechanical click buttons. Those types almost all have the same part with the same size and specs. Before buying a walkman you should make sure it has the part (usually contains one) by looking at the PDF service manual, in the exploded parts view.
|
|
Forum: Pentax K-30 & K-50
10-13-2016, 10:42 PM
|
| |
Normally it should not make any difference due to the voltage regulator IC, however the plunger is very sensitive to small voltage variations, I need to hook up my scope and read the values with different power cells.
Another fix would be increasing the tension on the counter spring of the arm attached to the plunger's horseshoe. I have not tried indeed.
|
|
Forum: Pentax K-30 & K-50
10-13-2016, 12:59 PM
|
| |
Hi,
DSLR and Flash tech is here. I work on all major DSLR systems.
When compared to others, Pentax is a very competent and high quality brand. They just suffered from bad management and supply chain issues since Hoya ownership. We will see how Ricoh would do.
Anyways...
I have been reading the posts and only a few have a clue on what the issue is.
First, the part called 'solenoid plunger' is defective. It is out of voltage specs, requiring more power (than normal plungers used in older models) to disengage and let the main metal aperture gear which runs inside an optocoupler to stop on time. When it does not release the horsehoe aperture gear has nothing to be stopped by and goes all the way down (i.e. F22)
If you sand or modify the plunger, it will very likely to stop disengaging since it is very delicate. The Russian method is wrong, DSLR are not make like Ladas.
The official solution is to replace the plunger with a good one from older models. It is a very hard to find part but you can use some donors.
On the other hand, K-1.K-3, K-5 and K-7 systems are entirely different. There is only one step motor to control the aperture and they are less likely to fail.
As far as I see, K-x (K-m), K-r and newer entry level models use solenoid controlled aperture block only and whenever there is a bad batch of solenoid plunger inside it will stop in the early life of the camera.
Good day to all!
|
