Pentax-DA*300 SDM fail

**chuck1955** · 08-02-2021, 04:29 PM

I got out my 300 mm f4 to try it out with my new K1ii, and darned if the autofocus is dead. I hadn't used the lens in awhile, but it had been fine the last time I did. I have not come up with any threads on this in a search of the forums. Is failure of the SDM motor a frequent fault on this lens that anyone knows of? I have had a copy of the infamous DA 16-50 SDM for years, known for this failure, with never a problem. I love the 300, and I guess I will be sending it in for repairs. Other lenses work fine on the K1ii, and the 300 does not work on another body, and the terminals are clean, and yes, the switch is on AF. There is no clamp on the lens that I can find. ARRGGGHHH!

vonBaloney · 08-02-2021, 04:33 PM

Haven't I heard about some of these SDM lenses needing to wake-up or go through some sort of "jump start" procedure if they haven't been used in some time?

**ramseybuckeye** · 08-02-2021, 05:33 PM

Originally posted by vonBaloney

Haven't I heard about some of these SDM lenses needing to wake-up or go through some sort of "jump start" procedure if they haven't been used in some time?

I've read that also, I wouldn't give up yet.

**termy** · 08-02-2021, 05:55 PM

Originally posted by chuck1955

I got out my 300 mm f4 to try it out with my new K1ii, and darned if the autofocus is dead. I hadn't used the lens in awhile, but it had been fine the last time I did. ARRGGGHHH!

Curious.
When you mention the lens was not used for some time.
How long was it it wasn't used?

A stretch of 3-4 months?
Or more towards 5-6 months?
Or what might it be?

**chuck1955** · 08-02-2021, 06:20 PM

A year at least - too much work, not enough photography.

**jatrax** · 08-02-2021, 06:22 PM

The 300mm is not one that is often mentioned as having SDM problems. Doesn't mean it can't fail though.

Try leaving it connected to the camera overnight. Some people have reported that can help.

You got me worried though as I don't think my DA 300 has been used in over a year. Just put it on and tested and the lens works just fine.

**GeeEmm** · 08-02-2021, 06:24 PM

I had the SDM fail on my 60-250, and sent it for repair, it was 8 or 9 years old and I wonder about failing lube, failing sealing rings overstressing the motor.. I was told by the distributor who did the repair that the motor was a new improved version.

I suggest you ask the same question when/if you send it in, it might be the same motor as in the 60-250 in which case you would have the new one put in (presumably), but it might be different too. Hopefully the replacements are going to give better service,

vonBaloney · 08-02-2021, 06:26 PM

A little googling and I found a suggestion to use Live View and keep trying to get it to focus -- turn the ring manually as well between attempts (with AF turned on).

**chuck1955** · 08-02-2021, 06:34 PM - **1 Like**

OK, I searched "jump start for SDM" and got a thread from this forum, suggesting holding down the AF button for a few seconds, plus turning focus ring back and forth a few times, and it worked. All good now.

One thing mentioned in that thread is storing lenses vertically rather than on their sides. My shorter lenses are mainly vertical, but I must admit the teles are on their sides. I will give it a try, (and make sure I use it more), but is that anything anyone has strong feelings about?

Thanks,

Chuck

**jatrax** · 08-02-2021, 06:49 PM

Originally posted by chuck1955

but is that anything anyone has strong feelings about?

Over the years there have been numerous 'solutions' to SDM issues. Leaving the lens on the camera to 'charge' it, using it frequently, turning the focus ring in some manner, etc, etc. As far as I know none of those methods have worked in all cases. So take them with a grain of salt. If it works for you, great, but I do not think there is any universal cure.

**UncleVanya** · 08-02-2021, 07:14 PM

Originally posted by jatrax

Over the years there have been numerous 'solutions' to SDM issues. Leaving the lens on the camera to 'charge' it, using it frequently, turning the focus ring in some manner, etc, etc. As far as I know none of those methods have worked in all cases. So take them with a grain of salt. If it works for you, great, but I do not think there is any universal cure.

Amen.

Also screwdrive conversion is an option. Not with the 60-250 but the da* 300 is easily converted.

The 300 and 200 are the lenses I convert the least as they seem the least failure prone.

**termy** · 08-02-2021, 07:55 PM

is good to know you managed to "wake it up".

Indeed.
I make it a point to use the DA300 at least once every 3-4 months.

Main thing is, just to ensure it doesnt get left unused for longer than 3-4 months.

So, sometimes i just mount it on the camera and then just make sure the AF motor move, even if am not shooting anything.

**GeeEmm** · 08-03-2021, 05:59 PM

I had problems with my 17-70, after the motor was first replaced I had a diary entry every two months to exercise the lens. I started getting problems anyway after maybe a couple of years or so, and the tricks about repeated focus attempts helped but did not stave off worsening. Sadly, it disappeared en-route for a second repair, so we'll never know whether it was the second SDM motor that was the problem, but I have my suspicions. The 60-250 was getting worse, I can't remember if it failed completely, or it was just so bad at the last event I used it at that I just switched to manual focus and then sent it off for repair. The 'kiss of life' tricks didn't work nearly as well on it as on the 17-70.

SteveEveritt · 10-15-2023, 02:33 PM

This is simply lack of use, the capacitor has drained and needs a recharge. Put it on your camera, press and hold the AF button and after a while it will burst back to life, I do it regularly with my DA*55 and have in the past with both the DA*16-50 and DA*50-135. Not an issue and certainly not worth butchering a perfectly good lens over.

**UncleVanya** · 10-15-2023, 05:17 PM

Originally posted by SteveEveritt

This is simply lack of use, the capacitor has drained and needs a recharge. Put it on your camera, press and hold the AF button and after a while it will burst back to life, I do it regularly with my DA*55 and have in the past with both the DA*16-50 and DA*50-135. Not an issue and certainly not worth butchering a perfectly good lens over.

Only some lenses respond this way. Many fail and won’t wake up. The likely issue is stiction not a capacitor based on what is known btw.

Also what do you mean about butchering?

08-02-2021, 04:29 PM	#1
chuck1955 Loyal Site Supporter Join Date: Sep 2012 Location: Upstate NY Posts: 35	*Pentax-DA300 SDM fail** I got out my 300 mm f4 to try it out with my new K1ii, and darned if the autofocus is dead. I hadn't used the lens in awhile, but it had been fine the last time I did. I have not come up with any threads on this in a search of the forums. Is failure of the SDM motor a frequent fault on this lens that anyone knows of? I have had a copy of the infamous DA 16-50 SDM for years, known for this failure, with never a problem. I love the 300, and I guess I will be sending it in for repairs. Other lenses work fine on the K1ii, and the 300 does not work on another body, and the terminals are clean, and yes, the switch is on AF. There is no clamp on the lens that I can find. ARRGGGHHH!

08-02-2021, 06:34 PM - 1 Like	#9
chuck1955 Loyal Site Supporter Join Date: Sep 2012 Location: Upstate NY Posts: 35 Original Poster	Success OK, I searched "jump start for SDM" and got a thread from this forum, suggesting holding down the AF button for a few seconds, plus turning focus ring back and forth a few times, and it worked. All good now. One thing mentioned in that thread is storing lenses vertically rather than on their sides. My shorter lenses are mainly vertical, but I must admit the teles are on their sides. I will give it a try, (and make sure I use it more), but is that anything anyone has strong feelings about? Thanks, Chuck

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08-02-2021, 04:33 PM	#2
vonBaloney Pentaxian Join Date: Oct 2011 Location: Albuquerque, NM Posts: 6,029	Haven't I heard about some of these SDM lenses needing to wake-up or go through some sort of "jump start" procedure if they haven't been used in some time?

08-02-2021, 05:33 PM	#3
ramseybuckeye Site Supporter Join Date: Apr 2009 Location: Hampstead, NC Photos: Gallery Posts: 17,294	Originally posted by vonBaloney Haven't I heard about some of these SDM lenses needing to wake-up or go through some sort of "jump start" procedure if they haven't been used in some time? I've read that also, I wouldn't give up yet.

08-02-2021, 05:55 PM	#4
termy Loyal Site Supporter Join Date: Jan 2019 Posts: 1,154	Originally posted by chuck1955 I got out my 300 mm f4 to try it out with my new K1ii, and darned if the autofocus is dead. I hadn't used the lens in awhile, but it had been fine the last time I did. ARRGGGHHH! Curious. When you mention the lens was not used for some time. How long was it it wasn't used? A stretch of 3-4 months? Or more towards 5-6 months? Or what might it be?

08-02-2021, 06:20 PM	#5
chuck1955 Loyal Site Supporter Join Date: Sep 2012 Location: Upstate NY Posts: 35 Original Poster	A year at least - too much work, not enough photography.

08-02-2021, 06:22 PM	#6
jatrax Site Supporter Join Date: May 2010 Location: Washington Cascades Photos: Gallery \| Albums Posts: 12,991	The 300mm is not one that is often mentioned as having SDM problems. Doesn't mean it can't fail though. Try leaving it connected to the camera overnight. Some people have reported that can help. You got me worried though as I don't think my DA 300 has been used in over a year. Just put it on and tested and the lens works just fine.

08-02-2021, 06:24 PM	#7
GeeEmm Site Supporter Join Date: May 2010 Location: Canberra Posts: 233	I had the SDM fail on my 60-250, and sent it for repair, it was 8 or 9 years old and I wonder about failing lube, failing sealing rings overstressing the motor.. I was told by the distributor who did the repair that the motor was a new improved version. I suggest you ask the same question when/if you send it in, it might be the same motor as in the 60-250 in which case you would have the new one put in (presumably), but it might be different too. Hopefully the replacements are going to give better service,

08-02-2021, 06:26 PM	#8
vonBaloney Pentaxian Join Date: Oct 2011 Location: Albuquerque, NM Posts: 6,029	A little googling and I found a suggestion to use Live View and keep trying to get it to focus -- turn the ring manually as well between attempts (with AF turned on).

08-02-2021, 06:49 PM	#10
jatrax Site Supporter Join Date: May 2010 Location: Washington Cascades Photos: Gallery \| Albums Posts: 12,991	Originally posted by chuck1955 but is that anything anyone has strong feelings about? Over the years there have been numerous 'solutions' to SDM issues. Leaving the lens on the camera to 'charge' it, using it frequently, turning the focus ring in some manner, etc, etc. As far as I know none of those methods have worked in all cases. So take them with a grain of salt. If it works for you, great, but I do not think there is any universal cure.

08-02-2021, 07:14 PM	#11
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,446	Originally posted by jatrax Over the years there have been numerous 'solutions' to SDM issues. Leaving the lens on the camera to 'charge' it, using it frequently, turning the focus ring in some manner, etc, etc. As far as I know none of those methods have worked in all cases. So take them with a grain of salt. If it works for you, great, but I do not think there is any universal cure. Amen. Also screwdrive conversion is an option. Not with the 60-250 but the da* 300 is easily converted. The 300 and 200 are the lenses I convert the least as they seem the least failure prone.

08-02-2021, 07:55 PM	#12
termy Loyal Site Supporter Join Date: Jan 2019 Posts: 1,154	is good to know you managed to "wake it up". Indeed. I make it a point to use the DA300 at least once every 3-4 months. Main thing is, just to ensure it doesnt get left unused for longer than 3-4 months. So, sometimes i just mount it on the camera and then just make sure the AF motor move, even if am not shooting anything.

08-03-2021, 05:59 PM	#13
GeeEmm Site Supporter Join Date: May 2010 Location: Canberra Posts: 233	I had problems with my 17-70, after the motor was first replaced I had a diary entry every two months to exercise the lens. I started getting problems anyway after maybe a couple of years or so, and the tricks about repeated focus attempts helped but did not stave off worsening. Sadly, it disappeared en-route for a second repair, so we'll never know whether it was the second SDM motor that was the problem, but I have my suspicions. The 60-250 was getting worse, I can't remember if it failed completely, or it was just so bad at the last event I used it at that I just switched to manual focus and then sent it off for repair. The 'kiss of life' tricks didn't work nearly as well on it as on the 17-70.

10-15-2023, 02:33 PM	#14
SteveEveritt Junior Member Join Date: Oct 2011 Photos: Gallery Posts: 36	This is simply lack of use, the capacitor has drained and needs a recharge. Put it on your camera, press and hold the AF button and after a while it will burst back to life, I do it regularly with my DA55 and have in the past with both the DA16-50 and DA*50-135. Not an issue and certainly not worth butchering a perfectly good lens over.

10-15-2023, 05:17 PM	#15
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,446	Originally posted by SteveEveritt This is simply lack of use, the capacitor has drained and needs a recharge. Put it on your camera, press and hold the AF button and after a while it will burst back to life, I do it regularly with my DA55 and have in the past with both the DA16-50 and DA*50-135. Not an issue and certainly not worth butchering a perfectly good lens over. Only some lenses respond this way. Many fail and won’t wake up. The likely issue is stiction not a capacitor based on what is known btw. Also what do you mean about butchering?