Kodak 750H Slide Projector: Tin Whiskers!

Mary’s folks asked me to figure out why the carousel on their Kodak 750H projector no longer turned. Some initial poking around suggested a problem with the solenoid, which only clunked when the projector was upside-down on the desk. I thought it might just have gummed up after all those years, but disassembling the thing (per the Service Manual and the usual Youtube videos) produced the root cause:

Kodak 750H Projector - broken solenoid link
Kodak 750H Projector – broken solenoid link

That explained the yellowish plastic fragments rattling around inside.

As predicted, it’s impossible to remove the solenoid without breaking the equally brittle focus gear in the process:

Kodak 750H Projector - stripped focus gear
Kodak 750H Projector – stripped focus gear

This is a sufficiently common projector to make repair parts cheap and readily available, at least for now.

Some of the interior sheet metal has a dark surface, likely heavy tin plating, covered with a thick coat of whiskers:

  • Kodak 750H Projector - tin whiskers
  • Kodak 750H Projector - tin whiskers
  • Kodak 750H Projector - tin whiskers
  • Kodak 750H Projector - tin whiskers

Touching a whiskered surface with masking tape captures the culprits, whereupon zooming the microscope and camera all the way in makes them just barely visible: they’re a few millimeters long and a few atoms wide:

Kodak 750H Projector - tin whiskers - detail
Kodak 750H Projector – tin whiskers – detail

I have surely contaminated the entire Basement Laboratory with tin whiskers. Makes me itchy just thinking about them …

5 thoughts on “Kodak 750H Slide Projector: Tin Whiskers!

  1. My 1973 vintage projector died due to broken nylon(?) pieces, this being in the mid 1990s. I bought a replacement, then a friend gave me an older, better one before he moved out of town.

    I think I’ve used the projectors a several years ago, but I scanned the slides and negatives when I still had a Windows box. I needed a third party program, since the Y2K vintage Epson software didn’t want to play with Win 7. The program had tolerable anti-fading corrections and did OK with the early ’60s slides my father had. (Ektachrome one year; Kodachrome II is a bit better behaved and that was his normal film.)

    I don’t know if I’ve used Xsane for film; it works fine with the scanner in normal mode.

    1. I did pretty much the same thing: scanned all the slides, packed them into a box, and one day I’ll trash the box: the color fading / shifting certainly hasn’t gotten any better in there!

      1. I have a vanishingly small number of slides that are Kodachrome, and both E4 and E6 Ektachrome does some interesting color shifts as the dyes age out. I used VueScan to handle the driver/scanning/color correction, and while not perfect, the results were Good Enough. Manual tweaking was available, if memory serves.

        Seems they now have a Linux version, with a freebie trial version. The Win 7 version I used in ’13 had a watermark to encourage spending the $40 to get the official version unlocked. Not clear if my old license would work with the new version. Closed source, yada yada.

        1. There has always been a Linux version of VueScan. I found that Hamrick Software is extremely generous about licensing, as their server allowed me to retrieve a license I bought ~2003 and use it to unlock a recent version. It’s closed source because scanner manufacturers won’t release full technical details of how their scanners work without an NDA.

          1. That’s good to know. Thanks!

            My license dates to 2013. AFAIK, I didn’t get the pro version, but Xsane does a sort-of decent job at text recognition.

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