Disassembly of DP1m - TOP PLATE

Hi there, I'm trying to get at the Shutter button circuit on my DP1m, and I'm stumped on how to remove the top plate.

To remove the rear cover, I found the excellent instructions given here by Johnson:

http://www.dpreview.com/forums/thread/3597760

Initial probing with a multimeter on about a half dozen exposed resistors nearby the shutter did not reveal a circuit that is directly connected to the shutter button switch. This is not too surprising, but hope springs eternal!

(I was inspired by this hack for a DP1s: <http://hgtweaks.blogspot.com.es/2010/09/sigma-dp1s-external-trigger.html>  No such luck for the DP1m apparently)

So the small circuit board underneath the top of the camera is going to have to come out. It appears that this circuit board under the top plate, together with the hot shoe, power and mode buttons, and shutter button/ring could all come out as one unit.  So far as I can tell, at least two data cables connect the top plate to the rear-facing circuit board.

Deep in the forward part of the camera, right under the hotshoe, there are two screws that evidently hold this unit in. I loosened them, and the top plate is loose on that side now.  But something else is holding the center/right side, and I cannot find it!

Has anyone taken out the main circuit board(s) to the right of the lens/sensor assembly, and are there some screws in there that hold down the top plate?

Thanks all.

SigmaTog thanks I'm familiar with those screws.  SOme of those already had to come out to remove the rear cover.

THe left (hotshoe) side of the top plate is loose.  Something is holding the right (shutter button) side.  That's what I'm trying to figure out.

This procedure is to access the top plate of the Sigma DP1m camera. The top plate includes the hotshoe flash connector, power button, mode button, shutter button and function ring. Attached to the top plate is a circuit board activated by these controls. Our purpose is to identify the shutter button contacts and add an electric remote release circuit to this circuit board.

Before starting on this project, educate yourself on static electricity discharge protection procedure and techniques. No matter how good you think you are, you are liable to break your camera doing this work, not to mention any warranties. Do not do this on your one and only Sigma camera, and don’t do it on a camera that you will need next week. I am merely an amateur. This is the first time I’ve taken apart my Sigma camera, and I can make absolutely no warranties of any kind that this is the best way to do it, or that it will work for you.

REMOVAL OF BACK COVER

Remove four screws that hold the rear cover on left and right side of camera. There are four screws around the tripod socket: contrary to intuition, only the “front” two need to come out.

Contrary to expectation, only the forward two screws (at the tripod mount) need to come out.

These six screws around perimeter are the same length and type - a fine thread, small black pan-head machine screw.

The spring clip in the hotshoe is removed with a small screwdriver to lift out the metal a little bit, up around the center contact.

Hot shoe spring clip finagled up and out

Once it is shifted over the center contact, the spring clip can be finagled out, revealing four screws. The rear two need to come out, they are longer, coarser, countersunk flathead silver machine screws. I stored all screws from this first step in a small film canister.

Remove the rear two screws off hot shoe platform.

Carefully separate the back, but know that there is a data cable that connects the back circuit board to a circuit board in the main body of camera. Disconnect at the rear circuit board. There is a very small hinging lever thing (brown color) that spans the width of the connector. Use your small screwdriver to lift that lever/bar, and the flat ribbon “cable” will come free.

Data cable needs to be separated from the back.

Finally you can remove the metal plate inside the camera body on the port (left) side of the camera, that is attached to the strap (I have a strap on my camera). That metal plate came loose when those screws were removed. Also note the small loudspeaker on that side, because we’ll be shifting the position of that later.

This is what your camera now looks like with the back removed.

REMOVAL OF CIRCUIT BOARDS

Next we’ll remove two circuit boards.

The first circuit board is held by three screws: two fine thread pan head silver screws in the corners along the starboard (right) edge, and one coarse thread screw near bottom center of camera. Remove them. Then the big flat circuit board connector data ribbon is lifted up - it comes off with very little pull using your fingernail.

Three screws hold the top circuit board to the camera. Data cable must first come off.

The first circuit board can now be lifted, hinged at the top of the camera by a wide data ribbon cable that is integral to the board. This cable is also integral to the circuit board now exposed: This second board has to come out next.

(Going forward, I replace the screws that I take out back into their threaded holes, after removal of the fastened item - this is a good way for me not to forget which screws go in what holes.)

Screws holding the second circuit board.

I’ll call this second board the SD card reader board, because it is under that big silver cover that the SD card is inserted / connected. Two other data ribbon cables connect to this board. One is the cable that went to the back plate - we can ignore it. The other cable needs to be disconnected. The connector is different on this one, with a little dark brown sliding thing on either end of the array of contacts. Use your small screwdriver to push back on both the little brown sliding things, and the data cable will come free.

Both sides of the SD board connector have a sliding clampy thingie you need to loosen.

As seen above, the SD reader circuit board also has three screws holding it down, two along the top, and another one in the lower left corner. Take these out and set aside. Now the last thing holding this board in place is the USB connector on the right - as it passes through an aperture in the camera body. I used my small flathead screwdriver to get underneath the two left side corners, to get the lift started. The board needs to lift on the left a bit first, then be shifted to the left a bit to allow the USB port to clear on the right, then it comes out. Remember it is connected to the first circuit board via a large integral data ribbon, so you’ll be handling both of them simultaneously, and they both come out as one piece.

The two main boards are out revealing a heat sink plate, easily removed.

Once this pair of boards is out, you’ll see what I think is simply a heat-sink for two processors that are on the bottom of the SD card circuit board. On the heat sink plate are two rectangular foamy bits with a some heat conducting grease on them. This plate comes out easily, after one screw on its left side is removed.

(This is a good time to put back some of the screws recently removed, holding these two circuit boards in place. Some are coarse thread and some are fine, and I swear you’ll get them confused later on, if you don’t replace them now).

REMOVAL OF BATTERY SUB-CHASSIS

Once the heat sink plate is out, you are presented with some confusion, as the next step is not clear. I figured that the various plastic and metal pieces, and a small circuit board, were all part of one item, which I will call the battery sub-chassis. The battery sub-chassis is mostly plastic, and once you recognize this structure, you can find the screws that hold down that plastic chassis into the camera.

Four screws hold the battery sub-chassis, one of them external through bottom of camera.

Remove: one screw that goes through the bottom of the front camera body/shell, another screw that goes into the lens/sensor chassis, and two screws at the top of the battery chassis.  Disconnect one small data cable from the small circuit board (again a tiny hinged affair locks down the ribbon).

Two small wires connect the TOP circuit board to the speaker at left side of camera. They are taped to and physically interfere with removal of the battery chassis. Cut the tape with a knife, to free the wires.

Don't cut the wires.  Cut the tape that holds the wires, to free them up out of the way.

Then finagle the speaker out from behind the lens/sensor chassis, giving some extra play in the wires. Now the battery chassis can come free of the rest of the camera, albeit again with some finagling and wiggling.

Battery chassis is out all in one piece.  It is part of what holds the camera top plate in place.

As is typical in this world governed by Murphy’s law, the circuits and actuators that are most likely to need service can only be accessed by first removing all the other components of the camera (the ones least likely to need service). Thus this very simple and practical modification has required the nearly complete disassembly of the camera! Fortunately, the innards of this camera appear designed / engineered well, so if one proceeds with care and patience, none of the disassembly is particularly difficult.

REMOVAL OF TOP PLATE

Now only two small screws remain, that hold the top plate into position. These are under the hotshoe plate, all the way forward, against the front of the camera. Now your small screwdriver needs some reach.

This is a L-R stereoview showing the two screws deep inside the camera, that hold the top plate.

Then we need to disconnect a data cable and a two-wire plug marked “mic” that goes to the microphone.

Data cable hinged connector binding.

"MIC" wire connector removal.  Loosen up with small screwdriver, then grab with small needle-nose pliers.

Finally: top plate out.  But we seem still a thousand miles from our goal.

With the top plate circuit board out, we can now meter various points to find a connection to the shutter circuit. Initial metering efforts reveal three points that react to shutter button depression, as follows:

I clamped onto the side of board to connect to ground

Bottom of the top plate circuit board.  Readings are in Ohms

Evidently contact no. 2 signals the half-press, and no. 1 the full press (shutter release).  But I'm concerned that the values are not zero resistance.  I must now research if shorting e.g. contact no. 1 to ground would actually release the shutter, or trash the camera!

I may disassemble the top plate further, if it is found that these contact will not provide me the necessary functionality. However, I am not hopeful about connecting to the switch directly. Surrounding the shutter switch on the top of this circuit board (picture shows the bottom of the circuit board) is a circular conducting “race” that is swept by an electrical contact attached to the dial which surrounds the shutter button. Thus it will not be possible to attach a wire to the switch directly, unless we had it come out of the camera through the shutter button itself (an exceedingly unattractive solution).

After some months hiatus, I disassembled the top plate of the Sigma camera, hoping to find electrical contacts with the shutter switch. Alas, no better contacts could be found, than I'd already found earlier. The switch itself is inaccessible due to the circular race of contacts surrounding it, which make it impossible to run a wire directly to the switch.

I brought the piece to my local camera professional, who was unable to help. As to my suggestion of soldering to the contacts showing resistance values, all he could do was shake his head.

So that's it for the Sigma Merrill cameras: there's absolutely, positively no way to wire in an electrical remote release, and therewith no way to electrically synchronize a release of the shutters of two cameras.

I have this idea that maybe there's a way to fire the camera through the USB port, but that would require hacking the camera OS, a task for advanced black hats which I haven't got!

This is unfortunate! This is a very affordable and handy camera that makes beautiful images. Alas, without electric release, this camera will remain of very limited utility for my stereoscopic work... I'll be looking for a replacement.

Thanks for your replies. The Sigma Quattros are unattractive to me due to their shape - since I'm searching for the ideal carry-around stereo rig. A pair of Quattros would be no less ungainly than a pair of Canon DSLRs (which I already have - a pair of 5D mk II).

THe holy grail is a compact high resolution camera, and the Merrills meet that requirement in a very unique way.

https://www.dpreview.com/reviews/image-comparison?attr18=daylight&attr13_0=canon_eos5dmkii&attr13_1=sigma_dp1m&attr13_2=sony_dscrx1r_ii&attr13_3=fujifilm_xpro2&attr15_0=raw&attr15_1=raw&attr15_2=raw&attr15_3=raw&attr16_0=100&attr16_1=100&attr16_2=100&attr16_3=200&attr171_3=on&attr199_2=high&attr199_3=normal&normalization=full&widget=1&x=0.33291772494465394&y=-0.15824731728652613

The DP1m has resolution comparable to my Canon 5D mk II (although the DPR image comparator seems to show the Sigma as quite a bit better, see above link).  The only other camera that is likely as good or better is the Sony DSC RX1R-II, and I have some evidence that it will take an electronic release.  THe problem is, it is currently TEN TIMES as expensive as the Sigma Merrills!

I may just end up waiting... currently I shoot MF film with a Sputnik when I go outside the studio, and while that is cumbersome in other ways, at least the results are good and I'm not down $6000 for more cameras;-)

Thanks again for your input!

Boris

Boris Starosta wrote:

After some months hiatus, I disassembled the top plate of the Sigma camera, hoping to find electrical contacts with the shutter switch. Alas, no better contacts could be found, than I'd already found earlier. The switch itself is inaccessible due to the circular race of contacts surrounding it, which make it impossible to run a wire directly to the switch.

I brought the piece to my local camera professional, who was unable to help. As to my suggestion of soldering to the contacts showing resistance values, all he could do was shake his head.

So that's it for the Sigma Merrill cameras: there's absolutely, positively no way to wire in an electrical remote release, and therewith no way to electrically synchronize a release of the shutters of two cameras.

I have this idea that maybe there's a way to fire the camera through the USB port, but that would require hacking the camera OS, a task for advanced black hats which I haven't got!

This is unfortunate! This is a very affordable and handy camera that makes beautiful images. Alas, without electric release, this camera will remain of very limited utility for my stereoscopic work... I'll be looking for a replacement.

If you are still interested, I found a way to add wired remote:

Sigma Merrill Wired Remote

docmaas wrote:

i'm interested.

mike

CT Don wrote:

Boris Starosta wrote:

After some months hiatus, I disassembled the top plate of the Sigma camera, hoping to find electrical contacts with the shutter switch. Alas, no better contacts could be found, than I'd already found earlier. The switch itself is inaccessible due to the circular race of contacts surrounding it, which make it impossible to run a wire directly to the switch.

I brought the piece to my local camera professional, who was unable to help. As to my suggestion of soldering to the contacts showing resistance values, all he could do was shake his head.

So that's it for the Sigma Merrill cameras: there's absolutely, positively no way to wire in an electrical remote release, and therewith no way to electrically synchronize a release of the shutters of two cameras.

I have this idea that maybe there's a way to fire the camera through the USB port, but that would require hacking the camera OS, a task for advanced black hats which I haven't got!

This is unfortunate! This is a very affordable and handy camera that makes beautiful images. Alas, without electric release, this camera will remain of very limited utility for my stereoscopic work... I'll be looking for a replacement.

If you are still interested, I found a way to add wired remote:

Sigma Merrill Wired Remote

Alright, then -

Disclaimer: I didn't photograph my work as i did it, so I'll use photos from this forum to illustrate, annotating them as necessary.  I may be modding another camera soon, in which case I'll update this post with my own photos.

First, a little theory of operation: Under the shutter button, are 2 switches. Actually, it's one unit with two independent switches inside, one on top the other (the Foveon of push button switches ;-)). When you press the button fully, the top switch closes first and then the bottom switch closes. The top switch tells the camera to focus. The bottom switch tells it to fire. A half press only causes the camera to focus. The common of each switch is connected to ground, so when the button is pressed, ground is applied to the appropriate circuitry to cause the camera to focus or to focus and fire.  The photo below shows the switch and pass throughs for the focus and shutter release signals.  Note that the switch is inside the contacts for the rotary dial that surrounds the shutter button.   Wipers from the dial (when it's in place above the switch) ride on these contacts.  The dial can be rotated continuously in either direction, preventing any wires connected on that side from exiting.

Shutter Switch

The first steps are to remove the back cover, two circuit boards, battery housing, and top plate, following the excellent instruction in this post: https://www.dpreview.com/forums/thread/3998582.

It isn't necessary to disassemble the back plate any further after it is out of the camera.

My method was to find the easiest place to attach 2 fine wires to the focus and fire sides of the switch and to bring them, and a ground wire, out of the camera body near the USB connector. I used wire wrap wire, which is insulated 30AWG solid wire.

Because the shutter switch is completely surrounded by the rotary switch, there is no way to attach wires directly to the switch and bring them out, without removing the rotary switch. From the photo above, it's obvious that the runs pass through the circuit board and continue on the other side. It's just a matter of finding out where the traces from the switch go after they pass through the board.

Here are the spots:

Focus and Trip Soldering Points

And, from a different angle:

Focus and Trip Soldering Points

I don't actually know (or care) what that component is, but I suspect it contains a pair of resistors that pull the voltage on the switches up, when the switches aren't actuated.

I soldered a wire to each of these points and routed them out of the camera. I followed the path of the microphone wires, then doubled back to bring them out near the USB connector, but there are other routes. In fact, I considered using the speaker wires to connect to the board and simply replacing the speaker with a connector, but for my purposes it was better to come out the other side.

Caveat - if you are going to duplicate this, you will need a very small soldering iron tip, very thin solder, a steady hand, and fine soldering skills.

My technique was to apply a small amount of solder to the leads of the component where I was going to attach the wires and also to the wires. Then, to position a wire against the lead of the component and touch the soldering iron to the pair. I soldered the wires perpendicular to the circuit board so as not to risk shorting a wire to any other component on the board.

For the ground wire, I chose to reinstall everything except the back cover, then pick up ground from circuit board #1.  There are myriad spots that will work.  I chose the one pointed out here:

Place to Solder a Ground Wire

I routed the 3 wires through the slot underneath the tab (next to the arrow) and out of the camera. Then, a filed a small notch in the back cover to accommodate the wires, put a small length of heat shrink tubing over the wires and replaced the back cover.

Reassembled

After testing that it worked by touching the ground wire to each of the others, I attached a 3-pin Molex connector and glued it to the USB/AV door.

Finished

Of course, you can use any connector of your choice. This one works best for my application, which is to install the camera in a hexacopter and fire it from an Arduino camera controller. I also attach an AV cable and transmit the video to a ground station.

Sigma AV on Ground Station

Thanks to all of you whose photos I re-used. I hope this is helpful.

-Don