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07-14-2011, 11:28 AM   #151
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I wonder if its a charger/battery issue as well. My pentax is at criscam waiting on a whole new circuit board. They cannot pin point what caused the surge to fry my board. I keep stressing that they need to figure that out before it happens on my new one!

07-14-2011, 11:28 AM   #152
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Theory

My mirror/shutter problems did not crop up until I had used the K-5 for several months. I may have had the camera in my car during a hot day which may have damaged a circuit somehow which didn't surface as a problem until I installed freshly charged batteries?
It's something to do with the batteries I'm sure. I just can't explain why the camera worked fine for several months and then suddenly went screwy!
07-14-2011, 11:35 AM   #153
Rin
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i must say though, the batteries that pentax uses are of great quality anyway. The indicators how full their are, are too much influenced by what you do at that moment. Not like the type sony uses for example which can give an exact estimate of when they are going to run out.
07-14-2011, 11:56 AM   #154
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Well i just posted on another thread about my camera.
Getting mine back from Pentax Japan.
New motor drives.
New shutters.
New mother board and components
Af adj.

2.5 weeks. Pentax Japan thank you. You are the best.

07-14-2011, 12:05 PM   #155
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QuoteOriginally posted by stanic Quote
yes, this could be really close...if anyone with a voltmeter could measure the voltage of different batteries...Phil, Jim, any posibility to measure ?
I'm using an inexpensive digital voltmeter. Don't know what the charge is on either battery so i'll take measurements now, and then later when i've recharged both. Also voltage drops when the battery is in use, i don't have any way of measuring battery voltage when installed.

Pentax Battery Pack ZE-LI90: 8.39 volts (this battery lists 7.2v nominal - don't know if this voltage is measured under load or not)

Pearstone D-LI90: 8.03 volts (this on a battery that lists 7.4v nominal - don't know if this voltage is measured under load or not)

I'll now charge both and report back.

It pays to check out this battery issue first, because thats the easiest fix if its defective. But the K5 must have circuits in it that regulate the voltage from the battery. Perhaps there's a batch of bad circuit boards that are not up to the task. I don't know if a firmware can adjust the regulation circuit, or whether a circuit board replacement is required. Just saying there are at least 4 parts to this mystery, the battery, the camera, the temperature of the previous 2, and the battery charger. Geez, not very complicated, huh.

Last edited by philbaum; 07-14-2011 at 12:17 PM.
07-14-2011, 12:07 PM   #156
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I have a mirror/shutter problem when the battery voltage is higher about 8 volts. A full battery has about 8,5 volts.
07-14-2011, 12:28 PM   #157
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QuoteOriginally posted by philbaum Quote
I'm using an inexpensive digital voltmeter. Don't know what the charge is on either battery so i'll take measurements now, and then later when i've recharged both. Also voltage drops when the battery is in use, i don't have any way of measuring battery voltage when installed.

Pentax Battery Pack ZE-LI90: 8.39 volts (this battery lists 7.2v nominal - don't know if this voltage is measured under load or not)

Pearstone D-LI90: 8.03 volts (this on a battery that lists 7.4v nominal - don't know if this voltage is measured under load or not)

I'll now charge both and report back.

....
Charging the Pentax Battery Pack only took a coupla minutes because it was my backup:

Pentax ZE-LI90 after charging: 8.41 to 8.42 volts (There are 3 contacts on the back of the battery. I assume they are separate cells that are run in parallel, one reads 8.41 and the other 8.42)

Now charging the Pearstone battery.
07-14-2011, 12:34 PM   #158
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thanks for very quick answer Phil
I am curious about the Pearstone`s voltage

07-14-2011, 03:03 PM   #159
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QuoteOriginally posted by stanic Quote
thanks for very quick answer Phil
I am curious about the Pearstone`s voltage
Summary:
a. I have 2 batteries, one a Pentax and one a 3rd party called Pearstone
b. The Pentax is my backup, when i measured its voltage:
Pentax before charging: 8.39 volts
Pentax after charging: 8.40 to 8.41 volts

c. The Pearstone was in my camera and had a few shots on it:
Pearstone before charging: 8.03 volts
Pearstone after charging: 8.40 to 8.41 volts

Conclusion: The final state voltage of your batteries does not depend on its
make, but on the charger and its settings, i.e. both the Pentax and the Pearstone ended up at the same voltage after charging.

Implications:
a. If one's battery is at too high a voltage, the problem has to do with the charger vice the batteries.

b. Jarovit in the message above stated that he has problems with mirror instability at voltages above 8 volts, and its his opinion that the battery gets charged at up to 8.5 volts. My testing confirms the last statement at final voltage.

c. Does anyone know if 8.4 to 8.5 volts is the expected fully charge value for our batteries??

d. I would note i've had my K5 for 4 months now and use it every few days, sometimes at up to 400 shots at an evening. I'm not having any mirror instability incidents (YET) with either battery that i've used, fully charged or not.

e. For those that have access to a digital voltmeter, it would be interesting to know what your fully charged DC voltage is (there are 3 contacts on the back of the battery with the fully right one being the hot voltage. there are 2 parallel circuits - checking the fully left one will give you one cell's voltage and then the 2nd contact from the left will give you the second cell's voltage. In my tests they have always been within .01 volt of each other.

f. Unless we find some difference in the performance of different chargers, its beginning to look like some problem with the camera. Reason: Jarovit is having mirror/shutter problems at voltages above 8 volts, and i'm not having the same problems (at least yet)

Side note:
I've finding that a digital voltmeter is a useful tool to determining which of your many rechargeable batteries are fully charged or not. I deal with not only the camera's battery, but with batteries for flashes and radio triggers. My voltmeter is about 8 years old and i may have paid $20 for it, can't remember. be sure to get digital vice analog for these measurements, much finer readings, if you buy one.

Last edited by philbaum; 07-14-2011 at 03:09 PM.
07-14-2011, 06:58 PM   #160
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Just to eliminate possibility of shutter release button connections to this issue I have played with this a little using button on grip. Same mirror problem, but I found something different on main switch than it is on K7. I do not know is this bad main switch or new feature.
When I put switch into preview position and later release my finger from it, switch does not coming back fully to ON position, I can make picture but I have to push it back until makes a little click and than reaches ON position.

After making about 500 pictures since last battery recharge I did not have mirror problem Today.

I have written about my issue to Pentax and United Camera Repair that I live close to.
Pentax responded Yesterday:
QuoteQuote:
Random shutter release in the K-5 has not been reported to us by PENTAX Japan as a known issue in the camera. Because we don't know exactly what the problem is until we examine the camera, we can't advise you whether it is something that can be corrected by United Camera and Binocular Repair. However, since the K-5 is still a relatively new camera I recommend you return your camera directly to PENTAX Imaging Company at the address listed below for examination.
interesting is that United Camera is listed on Pentax website as warranty repair shop.

United Camera answer is:

QuoteQuote:
repair for your issue will run $381. Please send the unit in with
your contact info and a copy of this email and we will contact you after we
receive.
They gave me a quote without checking my camera, do they already know what is wrong based on symptoms?
07-15-2011, 12:26 AM   #161
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thanks Phil for detailed summary
I have a feeling, that this malfunction could possibly be caused by bad production bath of the circuit boards...wild guess
could be relevant to check production date of affected cameras too...but that doesn`t include production date of the boards...oh well
07-15-2011, 09:48 AM   #162
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For what it's worth....
My K5 was fine for 4 months and the mirror flopping started right after I installed the Pentax brand batteries I had been using all along. The only difference was that the ones I put in had accidentally been topped off or charged twice due to some confusion between my wife and I. I don't know if this could have done anything to the camera. But I switched them out for my extra pair and got the same results. Now ever time I install fresh batteries the mirror flops away randomly until the battery level drops off. Then everything is fine until the next batteries are installed.
07-15-2011, 11:46 AM   #163
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If you are experiencing this problem and waiting to see what is done about it before sending your camera in for repair (as I was). Please call Pentax Customer Care at 800-877-0155 and report/complain about it.
The more they hear about this particular problem, the more likely they will be able to figure out the root cause of the issue.
07-15-2011, 02:49 PM   #164
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QuoteOriginally posted by philbaum Quote
Summary:
a. I have 2 batteries, one a Pentax and one a 3rd party called Pearstone
b. The Pentax is my backup, when i measured its voltage:
Pentax before charging: 8.39 volts
Pentax after charging: 8.40 to 8.41 volts

c. The Pearstone was in my camera and had a few shots on it:
Pearstone before charging: 8.03 volts
Pearstone after charging: 8.40 to 8.41 volts

Conclusion: The final state voltage of your batteries does not depend on its
make, but on the charger and its settings, i.e. both the Pentax and the Pearstone ended up at the same voltage after charging.

Implications:
a. If one's battery is at too high a voltage, the problem has to do with the charger vice the batteries.

b. Jarovit in the message above stated that he has problems with mirror instability at voltages above 8 volts, and its his opinion that the battery gets charged at up to 8.5 volts. My testing confirms the last statement at final voltage.

c. Does anyone know if 8.4 to 8.5 volts is the expected fully charge value for our batteries??

d. I would note i've had my K5 for 4 months now and use it every few days, sometimes at up to 400 shots at an evening. I'm not having any mirror instability incidents (YET) with either battery that i've used, fully charged or not.

e. For those that have access to a digital voltmeter, it would be interesting to know what your fully charged DC voltage is (there are 3 contacts on the back of the battery with the fully right one being the hot voltage. there are 2 parallel circuits - checking the fully left one will give you one cell's voltage and then the 2nd contact from the left will give you the second cell's voltage. In my tests they have always been within .01 volt of each other.

f. Unless we find some difference in the performance of different chargers, its beginning to look like some problem with the camera. Reason: Jarovit is having mirror/shutter problems at voltages above 8 volts, and i'm not having the same problems (at least yet)

Side note:
I've finding that a digital voltmeter is a useful tool to determining which of your many rechargeable batteries are fully charged or not. I deal with not only the camera's battery, but with batteries for flashes and radio triggers. My voltmeter is about 8 years old and i may have paid $20 for it, can't remember. be sure to get digital vice analog for these measurements, much finer readings, if you buy one.
i think i recall some people who where confronted with this problem very quick, so it doesnt seem too much time related i think.
07-16-2011, 07:36 AM - 1 Like   #165
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QuoteOriginally posted by LaurenOE Quote
Wow, watching that YouTube video was tough, but here is my take (as a software developer).

The Camera is a "Fly by Wire" device that doesn't have any real mechanical connections to firing the shutter. If touching/cycling any control on the camera causes the shutter to fire, then there is a glitch in the logic that fires the shutter circuit. Since it's a DSLR and the shutter itself would be too slow to have logic, as in the actual shutter circuit, the glitch is probably in the code up stream that interprets what control is actually being used. My guess is that there is a buffer that caches the camera settings just prior to an image being taken. Since any control on the camera is firing the shutter (when it is malfunctioning), then the buffer that accepts and stores the data prior to the shutter firing is either getting full or corrupted and then can't clear itself for the next shot - hence either multiple shutter slaps or any control firing the shutter.

The prior data is therefore not flushed and the camera fires again based on partial data in the "pre-fire" buffer that fires the shutter mechanism.

If I had access to the FW code, I would check the following.

1) Are there enough buffers allocated to accept the data in the pre-fire loop?
2) Is the cache being cleared and what data is retained for the next cycle?
3) How often does the pre-fire loop get data/samples from the camera controls?
4) Somewhere in the code, has there been a re-use of a parameter that got by the compiler but doesn't match what the pre-fire progam is looking for and therefore get's confused?
5) Are there voltage thresholds in the pre-fire program that cause confusion?
6) Are there temperature thresholds in the pre-fire program that cause confusion?

Ultimately I don't think they are clearing some cache somewhere or have enough buffers to both clear the old data and accept new data for the next shot.

Oh well.
This was great info. Thanks for taking the time Lauren!
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