protecting DSM LCD life

[digibloke]

The display just sits on small metal springs, kind of like a tiny suspension system. The metal clip applies just enough pressure to hold it in place and make contact with all the springs - no soldering. They're one of the easiest displays I've ever come across to replace, although one of the hardest to find a donor for :(

As for swapping a DSM for a field effect - I've got a Segtronic with a field effect display on the way from the States right now. When it gets here I'll see if the display works on my Walchron DSM and visa versa.

I think Nepros used the Microma display. It's different as they use solder contacts to the substrate. They're rarely working nowadays and are much harder to get at.

Replacing an IC? Way out of my depth but I'd love to see some pics.

[azimuth_pl]

thanx, I get the picture. I haven't had the time to take my few DSM's into pieces and make one fully working but I guess it works similar to the Gruen Teletime TNE LCD as pictured below:


Note that oval Optel DSM's use completely different modules then the more common square ones like Optcom, Segtronic.

Nepro's are identical to Microma however I'm not sure who made what as Microma used Swiss movements also. I have a few to work on with the displays detached so they will need some silver epoxy to attach them again.

[Old Tom]

I'm not sure that you can swop FE for DSM displays directly- the pin out may be the same but the drive voltages required are quite different. According to my book of words (Electronic Clocks and Watches by Michael S.Robbins published in 1975 by Howard Sams) back then the DSM display required 15 volts of drive voltage and the FE display about 7.5 volts so putting a FE display in a DSM watch would cause pretty rapid display failure.

Can confirm in rectangular Optel DSM watches the metal frame does slide off to one side to release the display panel (I took a Tell apart to play hunt the short). Just slide back to re-assemble.

[digibloke]

I guess the fact that the epsa-optel dsm displays flash on and off with every second whereas the field effect ones don't would also suggest that a swap won't work.

Azimuth - They're even more straight forward than those American micro systems Gruen lcd modules (love those watches though). Three screws and a clip is all that holds the whole thing together on the optels.

I've never seen one of the oval modules but I can't imagine that the connections to the lcd would be different to the later models as it seems to be the same display?

[azimuth_pl]

Thanks guys. this thread made me impatient to wait until Xmas so I'll change some priorities on other projects and work on the Optels this or next week.
I've just checked yesterday a TNE oval Optel module and the display is pressed onto the module with the metal frame which is screwed with 4 screws. The rest underneath the display look exactly the same as the DSM oval module I have. Perhaps some components are different but I will have to compare with both modules in front of me. I will post an update when I'm done.

[azimuth_pl]

courtesy of Rogerio from Brazil here are some pics showing the disassembly process of a DSM display from a rectangular Optel module:



for free picture posting I suggest using:
1) http://www.imageshack.us/
you don't even have to register (although possible) - upload, copy link, paste it on the forum and it's ready (use the link with capital letters URL)

2) http://photobucket.com/ - is more personal and has more options