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Robert Hart

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This has been a common failure in this camera family usually manifest firstly with blue rimming on hard contrast edges, becoming a soft and separate ghost blue image or no blue image at all, just a blue moon shape and a yellow cast in the rest of the image which users cannot white-balance. The fix from JVC is to replace the entire sensor block at considerable expense which given the obsolescence of these cameras is not justified.

Because of the manufacturing technique and the attachment of the sensors to the prism by adhesive alone with no other mechanical support, alignment of the detached sensor and reglueing it is not an option. However a means of attaching the blue sensor using two bridgepieces from the green and red sensors attached to jig hardware which remains on the individual sensors may be an option. From rough tests it sees doable, the issue being finding space to add small adjustment screws.

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Yea sadly that's the first generation camera. I worked with JVC as a beta tester on that camera and it was quite amazing for the time. It's sad they fell apart, but they got super hot, so one would think the issue was heat dissipation. I shot quite a bit with that camera and it always did me well. I don't think there is any way to easily fix and I bet most of them would have similar issues due to age. 

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Tyler. There is a little fan in there but the  blue sensor is highest in the group and probably receives more heat due to convection. There is another dynamic in play with the blue sensor in that the ribbon cable is only just long enough and imparts a lot of constant draw tension on the blue sensor board. Over time I suspect this has been the mechanism for the sensor coming off.

This can be converted into a pressure load by adding a spacer between the upper surface of the blue channel ribbon cable and the underside of the SD card slot assembly above.

Whilst doing a "live test" with the blue sensor bridged on one side to the other sensors and manually adjusting the free edge, I observed that the green sensor, whilst apparently firmly attached can flex very slightly on the adhesive and spring back. I did not try the red sensor. Sleeping dogs are best left to lie undisturbed.

When playing around inside a camera with a loose blue sensor with the right casework removed, take care to insulate between the edge of the blue sensor and the green sensor below it. They will short to each other and the camera will go dark. I thought I had destroyed it but it seems that this crashed whatever computer is inside it. When switched off and switched back on again it was fine so I dodged the bullet that time.

Phil. The  blue sensor coming off, creating a yellowish hue which won't whitebalance out has been a common failure mode with the JVC GY-HD*** camera family. Another failure I have with one of the three cameras I have here which has an intact sensor block is that half of the green channel has faulted leaving a purplish hue on one side. The fault is in the sensor and its downstream connector. The fault carries over to another camera when the block is installed in it.

That sensor block is my template for making the bridge pieces. Each sensor block will be individually slightly different because of manufacturing differences between sensors when the imaging chip is first installed. I am hopeful that the differences are so miniscule that simple tapered screw adjustments will enable the pixel rows to line up. The system was accurate enough to enable fine flying head adjustments on the old Sony EIAJ reel to reel video recorders. Shimming was another matter.

The adhesive seems to be similar to the water washable white bathroom sealer and is not dead hard but slightly pliant. It cleaned off from both the sensor face and the prism glass like bathroom sealer with a small wooden blade, a cut-down icecream stick. I don't like my chances but I have sent a request to JVC in the US asking what they used for adhesive. It appears that there are only four small points on the corners where there is adhesive in spots of about 1mm at most.

Edited by Robert Hart
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It seems that it can be done. This phone pic of the LCD screen is of the image from a JVC GY-HD111E with detached blue sensor relocated using rough cardboard bridges made from cereal packet cut with razor blades. Obviously the adjustments would have to be finer before the image on a large display screen would hold up but this is a good start. What a pity I did not do this a few years ago. I might have made a few dollars. Now I am just patching up museum pieces and there is no worth in it.


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  • 2 weeks later...

For those who have the endurance to remain curious, any bridge pieces which are made have to be vented to allow the small fan to push air through. As Tyler has mentioned above, the little processors on the PCBs the sensor chips are mounted to can get hot enough almost immediately to be on the pain threshold.

The bridge pieces are best made of formica or laminex sheet which is a thin thermosetting resin similar to bakelite. I have established with these it is possible to get a good alignment but perfection will only come from screw adjustments, not finger pressure and barely tightened screws.

Once I have established a position for the loose sensor I will make up different mounts attached to four conveniently located screws on the rear face of the mount to confirm to the restored position of the sens and use that instead of bridging all the sensors together.

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A small update.

Here is an illustration of a temporary support for the detached sensor which enabled me to establish just where in space it should be. 

The next step is to build a different support attaching to two pairs of screws and is microadjustable and yet enables enough clearance that the small dobs of adhesive can be spotted upon the four corners of the sensor to prism junction.

The material needs to be viscous so that it does not creep or wick in between the sensor and the prism through capillary action.

The adhesive appears to be a non-brittle material similar to white water cleanup bathroom sealer.

The bridgepiece is cut from formica or laminex which is a material similar to thermosetting resin or bakelite. It is insulative to avoid any chance of electromagnetic fields being introduced into the original steel jig pieces which function also as heatsinks. 

EMF seems to have been an issue because magnetic strips have been taped to the ribbon cables.

The bridgepieces block airflow so cannot be a permanent solution.

The far bridgepiece has been made to be a precise fit to another intact sensor block with three screws. There are elbows in the far jig pieces which have threaded holes which are conveniently are a match to the camera body screws. 

This cannot be an accurate exemplar because each sensor itself is very slightly different and must be aligned before the adhesive is applied in factory. It does however get very close. The bridgepieces are cut to be a very slight interference fit to the jig pieces.


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This clip is of a test alignment of the blue sensor in its temporary bridge pieces. You'll have to be quick to spot it just after the title. There remains a need for a rotatational adjustment the sensor. 

Edited by Robert Hart
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