[bdery]

True, but there are at least 4 of us on here, mostly with second hand lenses... That looks like a pattern (admittedly a small one)

Again, will all possible empathy to anyone having trouble with their product, 4 isn't a pattern.

[NigelS]

My len was purchased new in the UK with serial number 4581221.

It is interesting to note that the 28-105 lens has the same DC motors as a number of others, and SDM focussing eg
DA 18-135mm F3.5-5.6 ED AL [IF] DC WR
HD DA 16-85mm 3.5-5.6 ED DC WR
HD DA 20-40mm 2.8-4.0 ED DC WR
HD D FA 28-105mm 3.5-5.6 ED DC WR
HD DA 18-50mm 4.0-5.6 DC WR RE

There are threads for example on the DA 18-135 trying to find a solution repair for exactly the same issue as we are having with the FA 28-105 ! So it is a common thing with this Pentax genre of lens construction and I would be surprised if Pentax did not know about it, but they seem to be happy to keep selling the same unreliable stuff.

Buying a faulty DA 18-135 mm f/3.5-5.6 ED AL DC WR, is it worth reparairing it? - PentaxForums.com
18-135 lens stopped auto focus and live view - PentaxForums.com
18-135mm DA WR Problems Focusing at Lower Focal Lengths - PentaxForums.com

and on the 16-85
DA 16-85 AF issues - PentaxForums.com



Read more at: The 5 Lens Autofocus Drive Types Explained - Articles and Tips | PentaxForums.com

[dwgibson2000]

Hi VictorDA; Having sent my own lens in for repair last October in the UK it turns out that the UK service centre could not repair it so it was sent to the European service centre France who asked for more than £500 for a repair. (Cost of a new lens in UK is not much more.) Apparently it needs a complete new mechanical assembly. I declined their offer and asked for it to be returned. Two days ago they returned it to me. Good luck with anyone trying to get any help from Pentax these days. Customer service and support is non-existent! Good luck sending yours to the service centre, dont expect a quick repair!

This is all on the back of a disasterous attempt to get my K-1 (serial number 7344100) repaired last year. The UK service centre had that for nearly 9 months and eventually could not repair. They said it needed a new shutter, sensor and main circuit board and quoted a cost of £850 and offered a replecement camera at the cost of the repair. The shutter count on my camera was only 25k and was in very good condition, but I eventually decided to take that offer of a replacement. However, all I got was an older, worn out, broken, disfunctional K-1 as a replacement with a shutter count of nearly 70k (serial number 6350552). That was promptly rejected and returned to them !! They upped their offer to a replacement K-1mkII, for an additonal £320. Much against my better judgement I accepted that offer as well but despite me now buying a complete replacement camera, they would not return my original K-1. So if anyone now owns either of these K-1 cameras (serial 7344100 or 6350552), I would be very interested to hear from them.

What is most troubling to me is scary stories like NigelS stated. Wow! You should register those K1 serials on here with a warning/your story. What has happened to Pentax? That service & pricing is absurd. You'd think they'd give a break on repairs just to keep customers because that's enough to make a person change brands.

Anyway, my DFA 28-105mm serial is 4456904.

This all may not seem like a lot, several cases out of millions, but for every one reported you can likely bet there are 5 you didn't hear about and like previously stated, it's across several lenses using same parts. Seems to me to indicate Pentax under Ricoh quality control and service attitude has deteriorated immensely. Certainly not what it was when I 1st bought my K1000 or 2 Super programs bc I had a Canon A1 I took in for repair & the shop owner loaned me a K1000 he said he kept a few of on hand bc it was the only consumer 35mm camera on the market with metal body and all metal gears inside, unlike the A1 he said had all plastic gears. Oh well, I'm too old to change now and have too many cameras & equipment.

I'm toying with an idea to cannibalize another lens I got cheap, a 18-135mm, if the parts appear to be the same once I get in there. I'll let you know once I get in there. Should be interesting.

[VictorDA]

Hi all (especially @NigelS )
So I finally sent the lens for repair to "Nikken Techno France" in Paris, an authorised service center for Pentax.
The grand total (VAT included) is €218, consisting mostly of labour cost ("main d'oeuvre", 1.5 hr) and one unclear part ("replacement FPC GMR"). I'll try to get more info from them today if I can get someone on the phone.
It's already a better offer than the £500 mentioned before I guess. I will accept it because I can't get another lens, even used, for that price

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Last edited by VictorDA; 08-31-2023 at 08:14 AM.

[VictorDA]

So, it was not possible to get a technician on the line, but I understand from the receptionist that the part "fpc gmr" is a flexible electronic circuit. I guess it must have stopped working correctly for some reason.
Side note : it is my second dealing with this repair center, so far I am satisfied (we'll see when that repair is completed) and for anyone interested, they are also able to work in English

[JensE]

So, it was not possible to get a technician on the line, but I understand from the receptionist that the part "fpc gmr" is a flexible electronic circuit.

I'm afraid my DFA28-105 is affected as well, at the long end so far. A worn out flexible circuit makes sense, symptom-wise - a broken conducting trace on the circuit may still work when it's not bent. On one of my DA18-135 it's the wide end that stops without acquiring correct focus sometimes, which may however have different reasons.

[mikesbike]

There are threads for example on the DA 18-135 trying to find a solution repair for exactly the same issue as we are having with the FA 28-105 !

Actually, as I believe most who have been regular in PF for a length of time can verify, the DA 18-135mm lens has been exceptionally dependable with fewer reports of defects than most. Even though having the same AF technology, reports of problems with the otherwise excellent HD DA 16-85mm come along more often. Even some buyers of this lens new have had to return it more than once to get a good copy. So far, the HD DA 20-40mm Limited certainly has a fine record of dependability. These are two lenses of which functional problems seem comparatively rare, in terms of complaints showing up here in PF. But even these do not have an absolutely perfect record.

The older SDM lenses are a very different story. And some of these, which are very expensive, cannot be converted to screw-driven! This would be extremely frustrating, having parted with such a high cost only to have the AF conk out, and then having to face a very expensive repair for a new replacement part also subject to this failure!

So far, apparently like thousand of others, I have been very fortunate with my DA 18-135mm in particular, as I have had it for over 10 years, using it on numerous camera bodies, and it works today as well as it did when new. Maybe even better with the latest camera bodies. In fact, I have right along noticed its AF to be exceptionally fast and accurate among the lenses I own, even when used on some cameras not well-regarded for very good AF performance- like the original K-5. I am very careful with my gear, but if this lens should ever develop failure, which I do not expect to happen, I would replace it for sure with another new one. It is that good.

Another thing to consider- when buying used- one never knows what this item has been through. Resultant problems after some trauma or other might not show up until much later.

Any mechanical automation comes with some degree of increased chance for problems developing. Perhaps this is why Pentax has been insistent in sticking with the old screw-driven AF technology in their premium Limited series of prime lenses, with the rare exception of the new DFA HD 21mm f/2.4 DC Limited.

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Last edited by mikesbike; 03-10-2023 at 04:39 PM.

[JensE]

I'm afraid my DFA28-105 is affected as well, at the long end so far. A worn out flexible circuit makes sense, symptom-wise - a broken conducting trace on the circuit may still work when it's not bent. On one of my DA18-135 it's the wide end that stops without acquiring correct focus sometimes, which may however have different reasons.

I had sent in both for repair and received them back, with some replaced electronic parts according to the invoice, in total well below used prices, the DA is close. As I had bought another one, the DA18-135 is now a spare, the DFA28-105 back as my main compact and competent landscape full-frame lens. Both are essential parts of my kit, despite my love for primes, because they're hard to beat as quick and compact companions for outings with family and friends. Given that the DFA has served me well for 6+ years, spreading out its slightly higher repair cost, the 'wear' is rather insignificant in the overall expenses for my hobby. My DFA had an unusual kind of failure btw.: It always stopped just shy of correct focus for phase detection (viewfinder), but worked fine in live view - something that the repair shop had not encountered before.

[Sjak]

So, it was not possible to get a technician on the line, but I understand from the receptionist that the part "fpc gmr" is a flexible electronic circuit.

I have an old Tamron 10-24, and it does not focus properly at 24mm; it focuses just fine in the 10-23mm range, and I found this puzzling.

My local service-guy told me because a flexible contact in the lens in the lens is just too short, can cause unreliable connection at 24mm. According to him, this 10-24 will often develop this problem (also on other mounts.)

But just over 200 euro seems a good price for what is then effectively a serviced 28-105

[bdery]

one unclear part ("replacement FPC GMR")

FPC is Flexible Printed Circuit. Like your traditional green PCB but on a flexible substrate, useful for instance to wrap around a curved surface. It's probably the lens' main board.

[VictorDA]

Well friends, today I'm exhuming this thread to report on the conclusion of my D-FA 28-105's service.
I finally got the (or rather "a") lens back today, after 4.5 months waiting, and now I can retire (again) my old FA 28-70 f/4

There's a catch: it's not actually the repaired unit, but a brand new one in box with papers, at no extra charge.
Not necessarily a bad thing in my eye, since my unit, bought used, had a few other minor glitches and scratches.
The part I am less happy with is that:
1) there was no specific communication or explanation whatsoever on this change of plans (I had signed a quotation and paid for the repair);
2) makes me wonder how bad is the failure that it can't be fixed, and how likely it is to happen again...

Anyway, that's it, if others experience a similar issue, you might try to follow the same course of action.

[Sjak]

My experience with the service center in France was similar. Near-zero communication and VERY long waiting time. In addition, the issue I sent my camera for was not really addressed, although they apparently did some work on it.
On the other hand, for just over 200 euro, you have a brand new 28-105 which sounds like a good end to your adventure

[NigelS]

Hi @VictorDA
It has taken some time but glad you eventually got your lens ‘repaired’ with a complete set of new parts returned! Hopefully it will not give you any more problems. My lens is still working perfectly in manual mode but I have bought a second hand 28-105 that still works with AF and is probably a little better than my original. Not really sure I need two lenses but at least I have some spare parts. Now I just need to sort out the 18-135 …….

[VictorDA]

Hello @NigelS, great, thanks for the feedback. I suppose the budget for your 'repair' was close to mine anyway
Good luck with your 18-135 (although these are usually much easier and cheaper to find 2nd hand)!

@Sjak, indeed, I count myself lucky. Note that there are actually 2 accredited service centers in France for RI/Pentax: the historical one is P2MS and more recently, Nikken Techno which is the one I'm using. Both are located in or near Paris.