Kodak 750H Carousel Projector Repair An AT YOUR OWN RISK PROJECT by Klaus Wolter, Rev B, 3-26-2016 Here I documen the repair of my 750H carousel. A common problem with this projector, and all of the projectors in this series, is that Kodak used plastics in them that deteriorate with time. It literally becomes brittle and crumbles. This plastic is used on the end of a solenoid plunger that increments and decrements the slide tray. It s also used in a set of gears in the remote focusing system. Kits can be purchased to replace these parts but there is a dearth of how to information, hence this article. All of the screws are either P-2 phillips or 1/4" hex. A magnetic pickup tool comes in very handy. Here are the tools I used:
Left to right. Exato knife, magnetic pickup stick, long & short 1/4" nut drivers, tweezers, 1/4" wrench, flat bladed screwdriver, #2 phillips screwdriver, a wire brush on top and an old towel to place the projector on. Place the projector upside down on the towel and open all the covers as shown below. Remove the projection lens from the front and the lens, heat absorber and 300W bulb, shown in yellow and put them in a safe place, though this is not necessary for the. Adjust the forward foot, shown in purple, so that it s all the way down and remove the rubber foot. Remove the four phillips screws in the corners, shown in red.
Remove the bottom cover by lifting and pushing slightly forward to clear the front foot height-adjusting knob and set it aside. What you have now should look something the picture below. Be aware that Kodak changed the design slightly over time. The unit shown here is an older design with a power cord that plugs into the back of the machine. I have a newer 750H, which I have also made the same repair to, that has the power cord hard-wired into the unit and uses the motor winding as a transformer. The procedure is pretty much the same for both units and I will point out deviations as we get into it. Here I point out the location of the focus gears and the solenoid, which is hidden under some sheet metal. Start off by removing the twisty tie. Then remove the five 1/4" screws shown below. (All four of the machine screws are of the same length.) And remove the now loose plate and set it aside. EDIT: Well, screw #3 may not need to be removed after all. NOTE: Newer models will have the power cord attached to this plate.
You ll notice that my machine has seen better days, lots of oxidation, dirt and peeling paint. When I got it the motor was seized from rust between the spiny and non-spiny parts. I removed it, took it apart, cleaned off the rust, lubricated and reassembled it. It spins again! Next we ll remove the focus drive motor. Aren t you excited! Remove the three screws shown in red below. These are special shoulder screws with a sheet metal thread. Don t confuse them with the two solenoid screws the look almost the same except they have machine screw threads! Remove the motor and set it out of the way with the wires attached. This is a good time to lubricate the shaft at the bearing points with some electric motor oil. In my case I also connected the motor to a power supply and made sure it would run, which it did after a little persuasion.
Remove the solenoid screws shown in yellow above and in red below. I recommend removing them in the number order shown below so that the plate remains attached until the solenoid screws have been removed. Remember not to mix up the solenoid and motor mounting screws. NOTE: Newer models will have more wires in this area and sheet metal screw #3 might be a machine screw. Once reassembled, screw #3 can be loosened so the solenoid plate can be slid up and down with the aid of a flat blade screwdriver to adjust for maximum plunger travel when pushing the reverse button. This page will be referenced again later!
Next, follow the orange and blue solenoid wires to the wire nuts that secure them. Remove the wire nuts and extract the solenoid wires, being careful to put the wire nut back on the mostly orange bundle of wires so they stay together and don t get lost. NOTE: On the newer models, as shown in the picture below, the blue wire will be soldered to a lug on the motor. Unsolder this wire from the lug. Alternatively you could cut the blue wire and use a wire nut, etc. to reattach it upon reassembly.
It will be a little fussy to get it out, but now carefully remove the plate the solenoid was mounted to and the solenoid itself. The solenoid plunger might stay behind but it can be fished out. Notice that the end of the solenoid mounting plate is slightly bent where screw #3 secured it. This bend should be away from the sheet metal it was mounted to upon reassembly. The solenoid plunger will look like the one in the picture below. Remove the rivet and replace the broken actuator with your new one. It may be a tight fit but it ll go in. It s softish plastic to be careful not to damage it with sharp tools.
I used a center punch to splay the hollow end of the rivet as shown below. Tada! That bit of broken plastic is why your projector would no longer show slides when pushing the forward and reverse buttons. Now it s time to reassemble what you took apart. The bit of new plastic on the end of the plunger is flexible so it can be squeezed into the slot shown below. Slide the plunger back into the solenoid and position the assembly as shown below. Route the solenoid wires back through the hole they passed through before you took it out. Yeah, refer to the pictures above if you don t remember. Using a dull tool, one with no sharp edges that will cut or nick the plastic, and work the plastic end into the slot until the two cutouts engage with the sides of the slot. Again, do this with a plunger in the solenoid coil. Yes, more fussy work. I found it easier to engage one notch and then work the other in with a long, slender tool. And the fussiness continues! Work the solenoid plate back into its original location, making sure the piece at the end where screw #3 goes in is bent away from the sheet metal as previously mentioned. Secure the coil to the plate with the two shoulder screws with machine screw threads. Yes, not easy.
Secure the plate to the sheet metal with the third screw. At this point, replace the focus gears. Remove the old gears and clean the remaining plastic from the shafts and press on the new gears as shown below. I used large channel - lock pliers to gently push the gears on. Note: I used a #9 (0.196 ) drill bit to clean the flashing out of the hole through the larger gear and a #45 (0.082 ) drill bit to clean out the hole in the smaller worm gear before pushing them on. Reversing the disassembly procedure, reinstall the motor. Continue reassembly and reattach the solenoid wires being sure to route them as they were originally. Reinstall the plate and the twisty tie/ties as they were. At this point I suggest flipping the machine right side up and plugging it in to make sure everything works. Be careful not to zap yourself on exposed wiring!! You should now adjust the position of the solenoid, as previously mention, so that when the rearward slide advance button (reverse slide) is pushed that the solenoid doesn t buzz yet has maximum travel, with a satisfying clunk, as mentioned previously.
Finally, put the bottom back on, making sure to put the machine screw in the location as shown in the beginning. Clean and reinstall the optics and bulb, if you removed them. Now enjoy your working once again projector! At least my basket case projector works well and I hope yours does too.