LCD screen fading...What to do?

[Reli]

When the digits on an LCD screen start fading out, do you have to order a whole new screen from the manufacturer? Or is there anything else you can do?

 

[45player]

If they are fading evenly, and if they look ok if you look at them at a sideways look, the supply voltage may be getting weak, possibly due to a bad capacitor. If only a few segments are going off, it can be that the glass LCD plate needs resoldering where it meets the PC board. What kind of equipment??

 

[Reli]

It's a Grundig. I've heard they're notorious for this. It looks good from the side and from above, but from a head-on view the digits fade pretty badly.

 

[bobdog]

Have a look at the units PSU for the small capacitors, usually with values like 1uf @ 63v .....
Now the tricky bit.... a reasonable electrical competance will help .....
With the unit on, bring the hot tip of the soldering iron to the top of the capacitor for a couple of seconds (just to heat it up a little) and then take a look and see if the screen has brightened up.
You may have to do this to a number of small caps before you find the culprit....when you do, just replace the cap like for like...job done!

 

[Fatdog]

Welcome aboard, Bobdog. That is a very unique method of testing for sure.

 

[redbenjoe]

thanks for joining bobdog --
and for your help

are you related to fatdog

 

[bobdog]

Thanks for the welcome guys!
No relation to fatdog....Bobdog is my 19 year old collie dog...he's quite famous on one of the UK camper van forums!
You can use the cap heating trick to test buzzing power supplies too.....although as a rule it's usually the main smoothing that gives problems.
It's a lot quicker and easier than changing each one just to check it .
I was a TV tech for 20 odd years and the more I read here the more old 'tricks' come to mind......will post up when I have the next flashback!!

 

[Fatdog]

It's nice to have another "techie" in the midst.