My apologies for not providing pictures. Sixteen years ago I sold all my camera and darkroom equipment , planted hops and built a state of the art stainless steel micro brewery and have lived happilly ever after. A pint or two a day is worth a thousand pictures.
The photo diode that causes HDMI shutdown is a clear plastic device about 3/16" or so in diameter and about as high. It is located 1 1/8" behind the left audio input jack of INPUT 1. {If you print off the page from the service manual for the ANALOG PWB PATTERN (PARTS SIDE) (No.YA337 page 2-100 you can see it quite easilly. What I did is also printed out page 2-99 and taped the two pages together to show the complete circuit board. The printout is only slightly larger than the actual board. In the top right hand corner is the RCA jack. Measure 2" from the line at the right hand edge of the diagram to the left and measure 3/8" down from the line at the top of the diagram and that will put you in the middle of the 1/4" circle identified (if you can read it) as D492. You may also want to refer to page 1-24 (No. YA337) Fig. 7 in the service manual to help you viualize what you're doing but all of this is not necessary and may not be at all helpful if you're not used to looking at circuit boards and exploded view diagrams. Just follow the procedure below and all should go well.}
First make sure you have a P2 screwdriver, that's a #2 Philips head, in good condition. Some of the screws are tight and you will have to exert too much pressure on the screwhead if you have a worn or poorly fitting screwdriver and that could put undue torque on the circuit board where the connectors are soldered on. You should also have a 3/16" nut driver. You may need pliers or a crescent wrench, too.
Next, you will want to procure and prepare the material you will be using to cover the photo diode. I used a material called Cork Insulating Tape to cover the diode and the spot on the back of the board behind the diode so light can't get to it through the board. Cork Isulating Tape is used in the refrigeration industry to insulate compressor tubing that would otherwise frost up. It is made of tar and powdered cork and the stuff I have is 2" wide and 1/8" thick. It is black and self adhesive and comes in rolls of 30 ft. Probably any refrigeration shop would give you a half inch of the stuff which would be more than enough. I used scissors to cut two circles of a half inch diameter and molded one peice around the diode and stuck the other piece on the back of the board behind the diode. Now, this is not rocket science. I only used this stuff because I had a roll of it and I'm thinking that even a peice of chewing gum (chewed, then dried off) should be opaque enough to work. Test it by putting it over the end of a penlight flashlight in a dark room and see if any light comes through A peice of black electrical tape would work fine on the back of the board. Just make sure that your gum or whatever is not wet; you don't want to trap any moisture against the circuit board. Hopefully the chewing beforehand would remove any electrically conductive sugars, etc.
When you are ready, unplug your TV and pull out all the audio/ video cables from the back panel. We are going to remove the so-called BODY COVER. It sounds like a big deal but it's only the 12" high panel at the bottom back of the TV that has the ventlation slots and the lamp exhaust port. Under the butt end of the TV that sticks out there is an indented strip the width of the cover. There are 4 black screws there: remove them. There are little arrows molded into the plastic cover pointing to each screw you will have to remove. At the very bottom of the cover, looking like part of the base of the TV there is a screw at the extreme left and right of the cover: remove those 2 screws. At the top of each side or end of the cover there is a screw: remove those 2 screws. In the center of the BODY COVER, 2" up from the very bottom, there is one screw: remove it. You have now removed 9 screws. Now, according to a note somewhere in the manual, if you have an HD-56FH96, you will have two more screws to remove from the top right and left corners of the BODY COVER. In the 61" and apparently the 70", these are just empty holes so take note of which ones these are so you're not trying to put the screws in there on reassembly. Those are blind holes anyway so you couldn't get the screws in even if you tried, so don't sweat it. At the bottom of each side or end there is a plastic thing that sticks out that may look like some sort of screw: ignore those.
Now, look at the AV panel where all the RCA jacks are mounted. The BODY COVER is screwed to this panel with 5 silver screw through the black plastic tabs around the edges of the AV panel. Remove these 5 screws. The BODY COVER should pull off very easilly now, no force required. If it doesn't you must have missed a screw somewhere.
Now we need to remove the AV TERMINAL BOARD. Don't let the sound of this scare you; it's just the metal plate that has all the input/output labels on it. None of the connectors come off with it. (Note to those referring to the service manual: there is no need to remove the lamp cover or body bracket for what we're going to do. And for sure we will not be removing the main unit.)
There are 3 large silver screws along the bottom of the AV plate: remove those. Next, remove the 3 small silver screws: one is near the bottom of the plate under the OPTICAL OUT port, another to the left of the VHF/UHF connector and the third 1" to the right and up a bit from the ATSC/digital cable in connector
Next, remove the 8 small black screws. There are six in a vertical row to the left of all the composite video input jacks and two more lower down to the left of the composite video output jack and the audio output jack. As you will see when you get the plate off, the ANALOG board is sitting vertically to the left of all the connectors and each horizontal row of RCA jacks is in a solid stack soldered onto the ANALOG board. If you push on those black screws too hard during removal you will push the stack of connectors backwards and be putting undue stress of the solder connections. That is why you need a proper sized and well fitting screwdriver bit. Also, reach your left hand index finger around the back of the board and hold the connector stack where the back of each screw is to give support as you remove each screw so you don't push the stack back. Where there is an S-video connector in the row, support the back of that connector, since it's at the top of the stack in that row. These are just sensible precautions; don't let all this scare you from doing it even if you've never done this sort of thing before.
Next, locate the PC IN (D-SUB) connector. Using a 3/16" nut driver (a 5mm metric nut driver will also work) remove the hex standoffs at each end of the connector (turn CCW, just like any other screw.) If you don't have the right tool, you could use a pair of pliers, very carefully; those nuts screw out easilly once they are loosened.
The AV terminal plate should now pull away and off of all the connectors. It will still be connected to the TV by a cable connected to the SD (service card board) at the top of the plate but you will still have enough room to get to the photo diode. The plate will also be connected to a cable going to the VHF/UHF connector. There should be enough slack in the cable to allow you to pull the plate away from the RCA jacks so it will drop down an inch or so; that's all the room we need to do our work. If there is not enough slack in that cable, remove the nut on the VHF/UHF connector; there is a thin washer behind the nut. Be careful not to lose it. If you don't have the right size of nut driver, just use a pair of pliers or even a crescent wrench; once it's loosened, the nut will spin off easilly. (Note: the manual wanted the hex screws on the RS-232C connector removed as well, so this may be necessary on some models. It wasn't necessary on my 61")
Now locate the photo diode described earlier. Push your wad of gum over the diode and mold it down to touch the board all around. Be careful not to press the gum too thin on the top of the diode which might expose it to light. Put a peice of black electrical tape on the board behind the diode just to make sure no light gets through the board to the diode. Printed circuit boards are somewhat translucent and this seems to be a fairly sensitive diode and circuit design.
You will note, now that the back is off, that the ventilation slots on the left side of the body cover expose the ANALOG board and photo diode to any light that shines in those slots and you can't be covering those slots without risking overheating. This design is doomed to failure anywhere but a dark basement. Some have reported the cable card slot being covered helped. It didn't in my case and given the location of the slot I'd have to conclude that light from the ventilatilon slots is the real problem. Some have suggested that the purpose of the photo diode is to shut down the HDMI ports if the back is taken off in the name of content protection. I know little about this stuff (I specialized in scientific electronics) but it seems to be a token solution given the ease with which it can be defeated and at the same time has caused or will cause a problem for the majority of owners. Imagine the service calls, under warranty or after, that will be generated by this stupid design. It's anther one of those things that make me shake my head and wonder what the engineer was on when he came up with such an ill-conceived design.
Now, you can test it if you want, with the back off. I did. Nothing should explode. Just don't stick your fingers in there once you plug it in. Reset your ports if you have to with the procedure that everyone knows by now, althoght you don't have to unplug the TV after turning the TV off in the service menu #2 mode. Just wait for the cool down cycle to finish and power it up again, plug in an HDMI cable and cycle to the correct DIGITAL INPUT. Once you have a picture, shine a flashlight on the gum covered diode and if you did it right you shouldn't lose your HDMI ports.
If you tested your gum or whatever with a penlight as mentioned earlier, you don't have to even test it now. Just put the stuff back together in reverse order of taking it apart. Put all the nuts and screws back (black screws next to the RCA connectors, silver screws elsewhere) into the AV TERMINAL BOARD (the metal plate) but do not tighten any of them until you have them all in place just to make sure nothing gets skewed which might make the last screws hard to line up with the holes. Remember to reach a finger around to support the back of each connector stack as you put the black screws back. Then snug up, but don't overtighten, all nuts and screws. The hex nuts on the PC IN can be especially easy to snap off if you're too heavy handed, especially using pliers. Attach the AV plate to the chassis with the 3 silver screws, again, tightening only after all 3 are in their holes.
Fit the back into place and put the 9 or 11 screws back where you found them. Put in the 5 silver screws that hold the cover to the AV plate. Plug in your TV, reset your HDMI ports if necessary, plug in your cables again and you're done.
I hope this is useful to all. If you find an error or omission in the instructions please let me know and I'll revise the post.
