DM-15L Display

[GerryS]

Okay, a new question. I purchased a DM15L a while back (S/N 20384) which has a blemish in the extreme right side of the display. When I enter all zeros, the extreme right digit appears to be underneath the blemish so it doesn't affect the displaying of digits. When I first contacted Swiss Micros about this, it was suggested to put the calculator into a warm oven for a while and the blemish would disappear.

Obviously, I haven't done it because putting a plastic and metal calculator in an oven goes against my better judgement. So has anyone else had this issue and did putting the DM15L in a warm oven fix the issue? If yes, then what temperature and for how long?

Thank you for your help,
Gerry

[rprosperi]

While there are specific directions here (somewhere...), now that summer is upon us, you can also try leaving it, FACE DOWN, in direct sunlight for an hour or so, it may have the same curative effect as the heat from the oven. If you see a little bit of the blemish has disappeared, rinse and repeat, but I would not leave it out for multiple hours all at once.

Edit: Note that this advice applies only to Voyager family SwissMicros machines, and only for LCD blemishes that were present when you received the device when new. Do not use this technique for spots caused by damaged/leaking LCD.

[lrdheat]

I just put my DM 42 (WP-34S) out in the sun for 1+ hours. A blemish in the display on lower right (from it dropping out of my shirt pocket) was made worse! Fortunately, it is far enough to the right bottom corner to not interfere… be careful!

[rprosperi]

(06-18-2022 07:48 PM)lrdheat Wrote:  I just put my DM 42 (WP-34S) out in the sun for 1+ hours. A blemish in the display on lower right (from it dropping out of my shirt pocket) was made worse! Fortunately, it is far enough to the right bottom corner to not interfere… be careful!

That sounds like the LCD was damaged (and leaked) when it fell from your pocket, which is a totally different situation. The OP was referring to a blemish in the LCD as received when new, which seems to occur in a very small number of SM machines, and AFAIK only on Voyager family models. I don't think this has ever been reported on the Sharp LCD used on the DM42 and D41X.

Sorry that happened and I'll add some clarifying notes above to hopefully avoid this from happening again.

[mfleming]

A quick search on UV light and LCD turned up this link which confirmed a suspicion that UV from sunlight might damage the LCD organic material (the search also turned up a lot of links for sunburn protection - go figure)

https://abrisatechnologies.com/coatings-...l-failure/

If you want to warm the calculator in sunlight, it would be best to turn it face down first.

[lrdheat]

Yeah, I’d be careful…my spot, while not larger, and removed from all but the rightmost soft key menu, is now a solid black ugly spot. Might be better to leave things alone…

[blackjetrock]

(06-17-2022 07:30 PM)GerryS Wrote:  Okay, a new question. I purchased a DM15L a while back (S/N 20384) which has a blemish in the extreme right side of the display. When I enter all zeros, the extreme right digit appears to be underneath the blemish so it doesn't affect the displaying of digits. When I first contacted Swiss Micros about this, it was suggested to put the calculator into a warm oven for a while and the blemish would disappear.

Obviously, I haven't done it because putting a plastic and metal calculator in an oven goes against my better judgement. So has anyone else had this issue and did putting the DM15L in a warm oven fix the issue? If yes, then what temperature and for how long?

Thank you for your help,
Gerry

This might be what I saw on my SwissMicros calculator. I made a video about it here:

https://youtu.be/lOEOn0heLaI

I think my dots were caused by the calculator being left in cold conditions.

Andrew

[rprosperi]

(06-18-2022 09:25 PM)mfleming Wrote:  A quick search on UV light and LCD turned up this link which confirmed a suspicion that UV from sunlight might damage the LCD organic material (the search also turned up a lot of links for sunburn protection - go figure)

https://abrisatechnologies.com/coatings-...l-failure/

If you want to warm the calculator in sunlight, it would be best to turn it face down first.

Thanks Mark, I'll add that to my comment above.

When I got the initial advice from Michael about using an oven for one of my Voyager models, I used direct sunlight and it removed the blemish in about an hour, with no side-effect. But this suggestion that UV can do damage is troubling, so face-down does indeed make sense.

Thanks for the research and helpful suggestion.

[emece67]

I also had a DM15L with a leaked LCD and, after watching the YT video, decided to apply the oven method to fix it. Well, it worked, you can see the results here.

It was really unexpected for me to fix this. Wondering now if the same method will also fix original hp Voyager LCD displays.

Regards.

[rprosperi]

(06-20-2022 08:09 PM)emece67 Wrote:  Wondering now if the same method will also fix original hp Voyager LCD displays.

Generally speaking, no it won't. The most likely problem you have with an original Voyager LCD is a black spot along the edge where the LCD was broken and the material has leaked. This is permanent damage and cannot be repaired, the only choice is to replace the LCD with one from another Voyage of the same vintage (easiest way to tell is the battery compartments have the same contact types).

The technique with the oven applies to a specific potential mfg issue used on the LCD components used, and such heating is not a general purpose solution for other kinds of issues.

But thanks for providing clear evidence it works, this will help boost the courage of other owners to try the procedure. It would be ideal if you could explain the exact take-apart procedure and settings (how hot, how long to leave it in, etc.) you used.

[GerryS]

To All:

Thank you for this great information. I converted 110 degrees C to 231 degrees F so I'll set up my oven for a 90 minute run. It's a good idea to take the main board and LCD out of the case to minimize any possible damage to the plastic case and battery. This temperature may not melt the plastic case but it might soften it enough to leave marks when it's removed from the oven. I'll have to figure out a stand to put the main board on to keep hot spots to a minimum while it's in the oven.

I'll try it and see what happens.

Thank you,
Gerry