Faulty k10d mode dial

Northern Soul · 09-25-2010, 04:37 AM

The mode dial on my K10d is playing up. It works perfectly, except when you put it in manual it thinks you are in Bulb.

You can make it realise you are in Manual by pressing on top of the mode dial, so I suspect some loose connection somewhere - I'll take it apart later and have a look - but I just wondered if anyone else had had a similar problem.

Just my luck that it's one of the three modes I actually use (AV, P, M) that is playing up!

Adam · 09-25-2010, 08:59 AM

Quite a few mode dials fail for folks- see the similar threads below!

JeffJS · 09-25-2010, 09:14 AM

http://www.pentax-hack.info/firmware/k10_gx10/k10d_sm.zip

You may find this useful in your tear down..

Good luck with it.

bats · 09-25-2010, 12:37 PM

Jeff, there seems to be a password protectiing that zip file.

Djsajmy · 09-25-2010, 01:01 PM

Look in password.txt

Northern Soul · 09-25-2010, 02:30 PM

Thanks Adam and JEffJS - I had the manuals already, but just in case anyone else is thinking of doing this, DON'T SKIP THE DISCHARGING OF THE CAPACITOR!

I didn't have a resistor so I used a pencil lead wrapped in insulation tape and despite having the battery out all day it kicked like a mule when I discharged it - a flash, a bang, and the fear that I'd fried it.

I cleaned up the dial innards, but only quickly as I wanted to get it back together to see if I'd killed the camera completely - but fortunately I haven't.

The dial still doesn't work, but I'm not taking it apart again until I've been out and spend a few pence on a resistor - you can actually see the scorching on the pencil lead I used!

Northern Soul · 09-26-2010, 01:57 AM

From reading the other threads it seems Pentax just use contact cleaner in other cameras with simialr problems - off to town to get some later. Will keep you updated.

The dial itself has springy contacts on the bottom that touch a flexible circuit board underneath. As mine works if you press down on the dial I guess either the contacts (or a contact) have lost their spring, or are dirty.

Fingers crossed a 21p resistor and £3 can of cleaner sees it firing on all cylinders again.

Northern Soul · 09-28-2010, 07:06 AM

Update, in case anyone is interested.

The 950ohm resistor I bought was ok to discharge the capacitor once, but it melted the second time. Although Pentax don't specify a wattage in the document, I'd recommend getting a 1watt one.

Anyway, I took it apart again and it still doesn't work. I've also noticed that the metering mode dial doesn't work either. I hadn't noticed before, but I am stuck in centre-weighted. It's like having my old Praktica back!

Anyway, I've contacted Johnsons, who are the importer for Pentax in the UK, and I've been really impressed with their customer support.

Until I have another look under the hood I'm not sure what the problem is, but it can only be one of two parts that have failed if indeed there is a failure. Johnsons can provide these parts for £12 delivered, which seems very reasonable to me, and what's more they were very prompt in their email replies - so a big thumbs up for them!

jjdgti · 09-28-2010, 07:40 AM

Keep us informed on how did it go after replacing the parts.

Northern Soul · 09-28-2010, 09:29 AM

Will do jjdgti.

I'm going to have another go at cleaning it all first - when I have a bigger resistor. The problem is that there are wires running from the camera to the flash which I don't want to un-solder as my soldering skills are very poor, so there isn't much room to work.

I *think* that the flexible printed circuit board I need to replace just unplugs, but I could be wrong. I'll find my wife's camera and take some pictures.

It is nice to know though that if I do need to replace parts, Pentax will provide them, and at a very reasonable cost. It makes me happy to spend money on their products knowing that you can get parts.

JeffJS · 09-28-2010, 09:51 AM

If you manage to get it fixed you could find yourself with a little niche business. I see lots of posts with people having problems with mode dials, e-dials, and the like. Pentax may be good at providing parts but if they do the service, often times it's cheaper to replace the camera...

Those PC Wires are typically held into the connector via friction. There's usually a cover that slips down over the connector body that once released will allow you to extract the wire assembly. They aren't all like this but that's how most I've ever dealt with work.

Lloydy · 09-29-2010, 12:35 PM

I read somewhere that people who modify and repair flash guns use household halogen lamp bulbs to discharge the capacitors, because they don't blow so they can re use them.

Northern Soul · 10-13-2010, 05:15 PM

Well, I got a 2w capacitor at the weekend - another 26p spent!

I've stripped it down again, and it still doesn't work - or rather it is exactly the same - you can get manual mode, but only if you press down on the mode dial.

This is where the flexible PCB plugs in to the camera. I hoped it might be this that was loose, but it would seem not. It works exactly as JeffJS says - you slide out the black plastic part and the cable just comes out. The bunch of wires above that are the ones I don't want to unsolder, and it is two of those you need to short out with the resistor to discharge the capacitor for the flash. You can see some of the weather sealing too.

The second picture shows the contacts -on the right is the bottom of the mode dial, and on the left is the flexible PCB is contacts. The plastic holder with the PCB attached screws on to this (screw holes at 11 o'clock and 5 o'clock around the bottom of the mode dial).

The outer metal contacts are for the metering mode, and the inner ones are for the mode. I have bent one of the sprung pins on the metering mode, but that doesn't matter as they are in pairs and only one of each pair is needed.

If you disassemble the dial further by removing the centre screw it is just the plastic dial and a tiny ball bearing on a spring (so it stops in each mode position) - nothing electrical, so that cannot be the problem.

I don't think there is a problem with the connector in the first picture, which just leaves the contact between the flexible PCB and the pins - but I can't see a problem there either - bit the fact that it works when you press down on the mode dial suggests the issue is one to do with something not connecting properly somewhere!

There doesn't seem to be any damage to the PCB as far as I can tell - apologies for the rubbish quality of the pictures, they are from my phone.

Any ideas of what to try next much appreciated!

JeffJS · 10-14-2010, 02:51 AM

So the mode dial is not a switch but an encoder. Interesting. The fact you can push on it and make it work, tells me something on the PCB trace is worn out (assuming you've done the contact cleaner thing). You say you've already tried reshaping the spring contact that are attached to the dial so at this point I'd say the encoder (the pc trace part you've removed from the dial) needs to be replaced or the contact on the mode dial. It's probably all one assembly.

3200

wlachan · 10-14-2010, 03:06 AM

If it works when being pressed, it should not be something complicated. You may tighten the 2 screws in your last pic, clean all metal contacts with WD40 (spray on a cotton rod then wipe them), lift the brushes slightly and see if it works.

09-25-2010, 04:37 AM	#1
Northern Soul Veteran Member Join Date: Feb 2008 Location: The North of England Photos: Albums Posts: 494	Faulty k10d mode dial The mode dial on my K10d is playing up. It works perfectly, except when you put it in manual it thinks you are in Bulb. You can make it realise you are in Manual by pressing on top of the mode dial, so I suspect some loose connection somewhere - I'll take it apart later and have a look - but I just wondered if anyone else had had a similar problem. Just my luck that it's one of the three modes I actually use (AV, P, M) that is playing up!

09-25-2010, 08:59 AM	#2
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,594	Quite a few mode dials fail for folks- see the similar threads below! Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

09-25-2010, 02:30 PM	#6
Northern Soul Veteran Member Join Date: Feb 2008 Location: The North of England Photos: Albums Posts: 494 Original Poster	Thanks Adam and JEffJS - I had the manuals already, but just in case anyone else is thinking of doing this, DON'T SKIP THE DISCHARGING OF THE CAPACITOR! I didn't have a resistor so I used a pencil lead wrapped in insulation tape and despite having the battery out all day it kicked like a mule when I discharged it - a flash, a bang, and the fear that I'd fried it. I cleaned up the dial innards, but only quickly as I wanted to get it back together to see if I'd killed the camera completely - but fortunately I haven't. The dial still doesn't work, but I'm not taking it apart again until I've been out and spend a few pence on a resistor - you can actually see the scorching on the pencil lead I used! Last edited by Northern Soul; 09-25-2010 at 03:25 PM.

10-13-2010, 05:15 PM	#13
Northern Soul Veteran Member Join Date: Feb 2008 Location: The North of England Photos: Albums Posts: 494 Original Poster	Well, I got a 2w capacitor at the weekend - another 26p spent! I've stripped it down again, and it still doesn't work - or rather it is exactly the same - you can get manual mode, but only if you press down on the mode dial. This is where the flexible PCB plugs in to the camera. I hoped it might be this that was loose, but it would seem not. It works exactly as JeffJS says - you slide out the black plastic part and the cable just comes out. The bunch of wires above that are the ones I don't want to unsolder, and it is two of those you need to short out with the resistor to discharge the capacitor for the flash. You can see some of the weather sealing too. The second picture shows the contacts -on the right is the bottom of the mode dial, and on the left is the flexible PCB is contacts. The plastic holder with the PCB attached screws on to this (screw holes at 11 o'clock and 5 o'clock around the bottom of the mode dial). The outer metal contacts are for the metering mode, and the inner ones are for the mode. I have bent one of the sprung pins on the metering mode, but that doesn't matter as they are in pairs and only one of each pair is needed. If you disassemble the dial further by removing the centre screw it is just the plastic dial and a tiny ball bearing on a spring (so it stops in each mode position) - nothing electrical, so that cannot be the problem. I don't think there is a problem with the connector in the first picture, which just leaves the contact between the flexible PCB and the pins - but I can't see a problem there either - bit the fact that it works when you press down on the mode dial suggests the issue is one to do with something not connecting properly somewhere! There doesn't seem to be any damage to the PCB as far as I can tell - apologies for the rubbish quality of the pictures, they are from my phone. Any ideas of what to try next much appreciated! Last edited by Northern Soul; 10-04-2012 at 02:44 AM.

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09-25-2010, 09:14 AM	#3
JeffJS Inactive Account Join Date: Aug 2008 Location: Michigan, USA Photos: Gallery \| Albums Posts: 7,484	http://www.pentax-hack.info/firmware/k10_gx10/k10d_sm.zip You may find this useful in your tear down.. Good luck with it.

09-25-2010, 12:37 PM	#4
bats Senior Member Join Date: Sep 2010 Location: San Francisco Photos: Gallery Posts: 102	Jeff, there seems to be a password protectiing that zip file.

09-25-2010, 01:01 PM	#5
Djsajmy Junior Member Join Date: Sep 2010 Posts: 39	Look in password.txt

09-26-2010, 01:57 AM	#7
Northern Soul Veteran Member Join Date: Feb 2008 Location: The North of England Photos: Albums Posts: 494 Original Poster	From reading the other threads it seems Pentax just use contact cleaner in other cameras with simialr problems - off to town to get some later. Will keep you updated. The dial itself has springy contacts on the bottom that touch a flexible circuit board underneath. As mine works if you press down on the dial I guess either the contacts (or a contact) have lost their spring, or are dirty. Fingers crossed a 21p resistor and £3 can of cleaner sees it firing on all cylinders again.

09-28-2010, 07:06 AM	#8
Northern Soul Veteran Member Join Date: Feb 2008 Location: The North of England Photos: Albums Posts: 494 Original Poster	Update, in case anyone is interested. The 950ohm resistor I bought was ok to discharge the capacitor once, but it melted the second time. Although Pentax don't specify a wattage in the document, I'd recommend getting a 1watt one. Anyway, I took it apart again and it still doesn't work. I've also noticed that the metering mode dial doesn't work either. I hadn't noticed before, but I am stuck in centre-weighted. It's like having my old Praktica back! Anyway, I've contacted Johnsons, who are the importer for Pentax in the UK, and I've been really impressed with their customer support. Until I have another look under the hood I'm not sure what the problem is, but it can only be one of two parts that have failed if indeed there is a failure. Johnsons can provide these parts for £12 delivered, which seems very reasonable to me, and what's more they were very prompt in their email replies - so a big thumbs up for them!

09-28-2010, 07:40 AM	#9
jjdgti Veteran Member Join Date: Jun 2008 Location: NJ Posts: 1,824	Keep us informed on how did it go after replacing the parts.

09-28-2010, 09:29 AM	#10
Northern Soul Veteran Member Join Date: Feb 2008 Location: The North of England Photos: Albums Posts: 494 Original Poster	Will do jjdgti. I'm going to have another go at cleaning it all first - when I have a bigger resistor. The problem is that there are wires running from the camera to the flash which I don't want to un-solder as my soldering skills are very poor, so there isn't much room to work. I think that the flexible printed circuit board I need to replace just unplugs, but I could be wrong. I'll find my wife's camera and take some pictures. It is nice to know though that if I do need to replace parts, Pentax will provide them, and at a very reasonable cost. It makes me happy to spend money on their products knowing that you can get parts.

09-28-2010, 09:51 AM	#11
JeffJS Inactive Account Join Date: Aug 2008 Location: Michigan, USA Photos: Gallery \| Albums Posts: 7,484	If you manage to get it fixed you could find yourself with a little niche business. I see lots of posts with people having problems with mode dials, e-dials, and the like. Pentax may be good at providing parts but if they do the service, often times it's cheaper to replace the camera... Those PC Wires are typically held into the connector via friction. There's usually a cover that slips down over the connector body that once released will allow you to extract the wire assembly. They aren't all like this but that's how most I've ever dealt with work.

09-29-2010, 12:35 PM	#12
Lloydy Veteran Member Join Date: Aug 2007 Location: Shropshire, UK Posts: 1,114	I read somewhere that people who modify and repair flash guns use household halogen lamp bulbs to discharge the capacitors, because they don't blow so they can re use them.

10-14-2010, 02:51 AM	#14
JeffJS Inactive Account Join Date: Aug 2008 Location: Michigan, USA Photos: Gallery \| Albums Posts: 7,484	So the mode dial is not a switch but an encoder. Interesting. The fact you can push on it and make it work, tells me something on the PCB trace is worn out (assuming you've done the contact cleaner thing). You say you've already tried reshaping the spring contact that are attached to the dial so at this point I'd say the encoder (the pc trace part you've removed from the dial) needs to be replaced or the contact on the mode dial. It's probably all one assembly. 3200

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10-14-2010, 03:06 AM	#15
wlachan Veteran Member Join Date: Sep 2006 Location: Canada Photos: Albums Posts: 2,625	If it works when being pressed, it should not be something complicated. You may tighten the 2 screws in your last pic, clean all metal contacts with WD40 (spray on a cotton rod then wipe them), lift the brushes slightly and see if it works.