Can't see LCD clock upright, can when it's flat

[JoeG]

I have an older LCD atomic clock that used to have a nice bright display when it was standing upright. Now it's very difficult to see unless I lay it flat which displays all of the information clearly.

I've tried cleaning the screen contacts on the display and on the PCB as well. Nothing changed. Applying pressure around the edge of the case to see if it needs to make better contact does nothing.

Do LCD's just die over time, or can this be easily repaired? It's not worth spending any money for parts on, and it has also been discontinued long ago.

Thank you!

Joe

[Maximilian Hohmann]

Hello!

(07-08-2024 03:36 PM)JoeG Wrote:  Do LCD's just die over time, or can this be easily repaired? It's not worth spending any money for parts on, and it has also been discontinued long ago.

I have seen this happening mainly when the voltage applied to the LCD is getting too low, either due to bad batteries and/or battery contacts or to some component failure in the circuitry.
One thing worth trying might be to turn around the polarising filter in front of the LCD, some times this enhances the contrast.

Regards
Max

[Johnh]

If its battery powered, then that's the first thing to check if you haven't already. I have one that I changed the batteries on last week. iI was still showing the time, but the display had faded out except when viewing at a very acute angle.

The contrast on most LCDs does depend on viewing angle. On a calculator, if you have a contrast control, the perfect setting will depend a bit on which angle you mostly view it at.

[xerxes]

If it's powered by AA or AAA batteries, it might help to test lithium batteries as they have a higher voltage.

[BobVA]

A less likely but possible cause is failing electrolytic capacitors. LCD's typically need a negative voltage rail, usually supplied by a charge pump circuit, that may use an electrolytic capacitor or two. If that voltage starts to drop, the contrast will suffer.

[JoeG]

I tried different batteries, and replacing the capacitor. No improvement. The screen is just tired and old like me. So I dismantled it, saved the screws and the fine wire for bodge wire use in the future, and recycled the rest.

Thank you for the ideas!

Joe