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03-24-2015, 09:47 AM   #751
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Mirror flap plus flash problems

Hi al my camera which has the 1.11 FW is still at Pentax repairers UK Photopia,
and the main problem is that the flash while closed in the housing keeps firing, and then the mirror flapping, and then it just locks up nothing works.


I, will get rid of it when it comes back.


I already sent it away once 6wks ago and it came back with a FW upgrade only they never even checked it out, within one hour of getting it back, I got the above problems.
so this is the 2nd time now.


I must say although I love Pentax I have lost all confidence in them, and what I have been through with this camera.
its a silver edition serial num:2576211


I may go for the FF when it comes out but I will wait a few months to make sure its not Plagued with problems like the K3.
I know there are quiet a few whom have never experienced this problem, that's great.


But if you live in the UK then the Pentax repairers here are c--p to say the least.
and they treat the customer like that.


I was flabbergasted when that camera came back from Pentax authorised Service Centre Johnsons Photopia Ltd.


with all the faults that shows me it was NEVER checked


No use going on and on.


You all have a nice day


Tom G

04-01-2015, 03:18 PM   #752
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Im sad to report that after being serviced by Precision (who did a great job cleaning and getting AF back to factory specs btw) the dreaded mirror flap has recently returned while on vacation. Guess I'll be sending it back once again. Sigh.

Michael
04-01-2015, 05:58 PM   #753
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QuoteOriginally posted by MJSfoto1956 Quote
Im sad to report that after being serviced by Precision (who did a great job cleaning and getting AF back to factory specs btw) the dreaded mirror flap has recently returned while on vacation. Guess I'll be sending it back once again. Sigh.

Michael
04-03-2015, 09:17 AM - 1 Like   #754
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I am a retired electronics engineer from NASA's Manned Space Flight Center. I will give you my explanation of what is causing the mirror flap problem. There is a transistor which causes the mirror to be raised. Normally a signal from the printed circuit board drives the signal input pin on that transistor - however the grounded pin on the transistor can also serve as a signal input. This happens when the impedance of the ground itself is too high (for example the wire connecting the transistor to the battery negative terminal might be too long or too small in diameter. A current passing back to the battery from another operation can create a trigger voltage for the mirror control transistor causing it to fire. The fire signal voltage disappears when the mirror is raised - then reappears when the mirror goes back to its proper condition and the cycle repeats - causing the mirror flap.

This is not something which software can ever fix; only a redesign of the hardware can fix it. Finding and fixing an intermittent problem like this is probably the most difficult problem electronics engineers can face: there is nothing wrong with the digital design, it is a weird analog ground impedance problem. Even putting an oscilloscope probe on the circuit board to try to examine the problem can make it vanish. it is like chasing a ghost.

04-03-2015, 09:31 AM   #755
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So I think I had my 2nd experience with mirror flapping... K-3 with the latest firmware. Around 4-5 weird movements and then it stopped by itself. No photos saved during the mirror flapping.


My K-3 counter shows approx. 10,000 shots. This flapping problem... is this something what might be getting worse? Should I grapple with complaint or simply learn to live with the fact that once upon a time the mirror will get crazy?


If Houston Bob (right above me) is right, it does not look like something what could really be fixed - I'll only be without my camera for (many?) weeks.... Should there be 2 similar mirror "incidents" per each 10,000 shots, I would say I don't care...
04-03-2015, 09:49 AM   #756
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QuoteOriginally posted by HoustonBob Quote
This is not something which software can ever fix; only a redesign of the hardware can fix it. Finding and fixing an intermittent problem like this is probably the most difficult problem electronics engineers can face: there is nothing wrong with the digital design, it is a weird analog ground impedance problem. Even putting an oscilloscope probe on the circuit board to try to examine the problem can make it vanish. it is like chasing a ghost.
In regards to chasing the ghost, I had to grin. It is the nature of intermittent problems that putting a monitor in place often biases the system toward stability. Your description of a possible cause is compelling, though I would think that circuit isolation within most production quality chips* along with modularization would make this sort of thing unlikely.

I am not saying that what you describe is not happening, only that it might be happening at a higher level. I say this because there are side-affects to the runaway mirror when it happens. Whether such is accessible to a fix-in-code depends on the hardware architecture and how component state is managed. A random trigger may exist, but it may be possible to modify the finite state interactions between control modules such that the trigger is ignored. The false triggering is a logic hole, after all. The descriptions of the service center fix seem to point to this sort of solution.


Steve

* It is my understanding that the mirror and shutter controllers and assemblies are off-the-shelf components from established industry suppliers (e.g. Copal) flashed to Pentax specification.
04-04-2015, 11:02 AM   #757
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QuoteOriginally posted by HoustonBob Quote
I am a retired electronics engineer from NASA's Manned Space Flight Center. I will give you my explanation of what is causing the mirror flap problem. There is a transistor which causes the mirror to be raised. Normally a signal from the printed circuit board drives the signal input pin on that transistor - however the grounded pin on the transistor can also serve as a signal input. This happens when the impedance of the ground itself is too high (for example the wire connecting the transistor to the battery negative terminal might be too long or too small in diameter. A current passing back to the battery from another operation can create a trigger voltage for the mirror control transistor causing it to fire. The fire signal voltage disappears when the mirror is raised - then reappears when the mirror goes back to its proper condition and the cycle repeats - causing the mirror flap.

This is not something which software can ever fix; only a redesign of the hardware can fix it. Finding and fixing an intermittent problem like this is probably the most difficult problem electronics engineers can face: there is nothing wrong with the digital design, it is a weird analog ground impedance problem. Even putting an oscilloscope probe on the circuit board to try to examine the problem can make it vanish. it is like chasing a ghost.
I'm not an engineer, but I was told by a confidential but very credible source that occasional out-of-bounds voltage fluctuations in the mirror circuit were causing the mirror flutter. This was fixed by applying a software upgrade (provided by the factory) to a specific control circuit in my camera by the former repair center in Chandler, Arizona. This keeps the mirror control voltage within specific bounds. This is NOT the user-applicable software upgrade, but can only be applied by an authorized repair station to that particular circuit. This was done to my K-3 in June, 2014 and I have had NO further incidents of mirror flap. Previously, from Nov. of 2013 to June of 2014, I had two flapping incidents. Since the software fix, I have had zero problems with my K-3, and I use it constantly. So I think your assertion that this "...is not something which software can ever fix..." is at variance with the facts. Again, my apologies for not being a technical guru - I'm just reporting my experience with this problem.

John

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04-04-2015, 02:50 PM   #758
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Follow up on my mirror problem:

I sent the K3 off and received it in just 7 days. So far, no problems. Fingers crossed.

04-04-2015, 04:24 PM   #759
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QuoteOriginally posted by PALADIN85020 Quote
I'm not an engineer, but I was told by a confidential but very credible source that occasional out-of-bounds voltage fluctuations in the mirror circuit were causing the mirror flutter. This was fixed by applying a software upgrade (provided by the factory) to a specific control circuit in my camera by the former repair center in Chandler, Arizona. This keeps the mirror control voltage within specific bounds. This is NOT the user-applicable software upgrade, but can only be applied by an authorized repair station to that particular circuit. This was done to my K-3 in June, 2014 and I have had NO further incidents of mirror flap. Previously, from Nov. of 2013 to June of 2014, I had two flapping incidents. Since the software fix, I have had zero problems with my K-3, and I use it constantly. So I think your assertion that this "...is not something which software can ever fix..." is at variance with the facts. Again, my apologies for not being a technical guru - I'm just reporting my experience with this problem.

John

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Thanks for the additional background. Your explanation along with HoustonBob's are the best I have heard in regards to the runaway mirror problem.


Steve
04-04-2015, 04:24 PM   #760
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I sent my K-3 off as well... I talked to Monique at Ricoh customer support, who suggested I just send the camera off to Precision right away (my purchase date was 5/18), without filling in the online repair form. I stripped the camera of all removable items, leaving just a body cap. And a purchase receipt with brief note that the problem was mirror overrun.

Tracking indicates it's in Windsor Locks CT as of early this morning, due for delivery to Precision on Monday morning. I will be interested to see how it works out from here...

I have had previous experience several years ago with Precision repeatedly failing to repair problems with a Konica Hexar RF over about 9 months of back and forth, and while I think it's ok now I have no confidence in that rig any more.

Fingers crossed here also!

Last edited by Dougg; 04-04-2015 at 04:30 PM.
04-06-2015, 06:04 AM   #761
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Quick upgrade on my problem with k3

Hi all again.


After getting in touch with eBay whom now have agreed that I send the k3 back to the seller and they will give me a full refund,
eBay have given me until the 16th April.


so as the camera was sent to the shop in Cardiff they in turn sent the camera to Photopia for repairs, after three weeks I phoned them up as I need the camera back to send to the seller,
they now inform me that it would take an other 3wks till they get parts,
I have now arranged on Wed/1st April to have the camera returned unfixed as I have a deadline from eBay.
So due to the holiday this weekend I hope to get the camera by Tues 7th /Wed/8th and then it will be sent back to the seller.
( eBay sent me a collect+ label so it will be tracked )


all I have to do then is post eBay the tracking number and I should have my refund by next week all going well.
This whole dilemma has been an experience and I will never buy a used camera from eBay just not worth all the hassle


Thanks to all for the advice
Tom G
04-07-2015, 12:45 AM   #762
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QuoteOriginally posted by Tom777 Quote
Hi all again.


After getting in touch with eBay whom now have agreed that I send the k3 back to the seller and they will give me a full refund,
eBay have given me until the 16th April.


so as the camera was sent to the shop in Cardiff they in turn sent the camera to Photopia for repairs, after three weeks I phoned them up as I need the camera back to send to the seller,
they now inform me that it would take an other 3wks till they get parts,
I have now arranged on Wed/1st April to have the camera returned unfixed as I have a deadline from eBay.
So due to the holiday this weekend I hope to get the camera by Tues 7th /Wed/8th and then it will be sent back to the seller.
( eBay sent me a collect+ label so it will be tracked )


all I have to do then is post eBay the tracking number and I should have my refund by next week all going well.
This whole dilemma has been an experience and I will never buy a used camera from eBay just not worth all the hassle


Thanks to all for the advice
Tom G
I don't know what kind of deal you got for the used camera but in your shoes ........

On finding the camera faulty contact the seller negotiate either full refund return or massive discount for faulty goods (discount mutually agreed)

I don't see how the camera can be at 'repair' when you obviously still in negotiation of the sale with the seller or their agents (ebay)

I have never had any issue buying 2nd hand good from ebay and even when they have not matched the description have always been able to reach a mutually agreeable solution with the sellers.

I think your problem is trying to run non compatable contractual arrangements at the same time neither of which the seller or Ricoh can control to your satification
i.e
Buying camera
claiming warranty

As your probably aware in the UK your warranty is via the seller and not the manufacturer (even though manufacturer provides the warranty) so in this case you should have been dealing with the seller (providing they offered warranty fro 2nd hand goods).
Any direct dealings with the manufacturer are really dependent on their good will which luckily most/all UK operating manufacturers tend to live up to and happily handle direct warranty claims.

Last edited by awaldram; 04-07-2015 at 12:50 AM.
04-07-2015, 11:04 AM   #763
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QuoteOriginally posted by awaldram Quote
I don't know what kind of deal you got for the used camera but in your shoes ........

On finding the camera faulty contact the seller negotiate either full refund return or massive discount for faulty goods (discount mutually agreed)

I don't see how the camera can be at 'repair' when you obviously still in negotiation of the sale with the seller or their agents (ebay)

I have never had any issue buying 2nd hand good from ebay and even when they have not matched the description have always been able to reach a mutually agreeable solution with the sellers.

I think your problem is trying to run non compatable contractual arrangements at the same time neither of which the seller or Ricoh can control to your satification
i.e
Buying camera
claiming warranty

As your probably aware in the UK your warranty is via the seller and not the manufacturer (even though manufacturer provides the warranty) so in this case you should have been dealing with the seller (providing they offered warranty fro 2nd hand goods).
Any direct dealings with the manufacturer are really dependent on their good will which luckily most/all UK operating manufacturers tend to live up to and happily handle direct warranty claims.


You don't no the full facts and I cant be bothered writing an explanation at this time if you new the facts it may change your tune,
but you come across as a bit aggressive.
so I will leave it at that cant be bothered getting into a slanging match about your comments


if you relay want me to explain everything then I will just not to-night
Tom G
04-07-2015, 12:12 PM   #764
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Sorry about your problems and all, but I'm not sure I understand how you read awaldram's comment.

QuoteOriginally posted by Tom777 Quote
You don't no the full facts and I cant be bothered writing an explanation at this time if you new the facts it may change your tune,
And he states as much.

QuoteQuote:
but you come across as a bit aggressive.
How so? Questioning your actions is not the same as being aggressive. I mean, when you post something you must expect people might comment on it - and comment based on the information given. From what you have written so far it does look like you have sent off an item for repair before trying to sort any problems out with the seller. You may well have good reasons for doing things in that order, but it's hard to see that from your posts.
04-13-2015, 01:34 PM   #765
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QuoteOriginally posted by HoustonBob Quote
I am a retired electronics engineer from NASA's Manned Space Flight Center. I will give you my explanation of what is causing the mirror flap problem. There is a transistor which causes the mirror to be raised. Normally a signal from the printed circuit board drives the signal input pin on that transistor - however the grounded pin on the transistor can also serve as a signal input. This happens when the impedance of the ground itself is too high (for example the wire connecting the transistor to the battery negative terminal might be too long or too small in diameter. A current passing back to the battery from another operation can create a trigger voltage for the mirror control transistor causing it to fire. The fire signal voltage disappears when the mirror is raised - then reappears when the mirror goes back to its proper condition and the cycle repeats - causing the mirror flap.

This is not something which software can ever fix; only a redesign of the hardware can fix it. Finding and fixing an intermittent problem like this is probably the most difficult problem electronics engineers can face: there is nothing wrong with the digital design, it is a weird analog ground impedance problem. Even putting an oscilloscope probe on the circuit board to try to examine the problem can make it vanish. it is like chasing a ghost.

GREAT WORK DEAR WATSON!!!

will Pentax hear you though and fix that mess? a few unhappy k-3 owners it seems could benefit from your knowledge!
thanks for all your hard work on this issue
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