Faint L.C.D. Display??

D

Derek

Guest
Before I start, I have tried a Google search, and no luck.

I have a digital, hand-held tachometer for checking the r.p.m.s of
"stuff". I can read the display, but certain bars of the display are
very faint and I must play with the angle to see the numbers.

My question is this, is this (usually) a degradation of the display
itself, or is it something like poor contacts inside? I know this is a
vauge question, but any help would be appreciated. I have opened the
unit and tried re-seated everything, but I'm nervous to go too far. I
have done the obvious like replacing the battery and adjusting the
contrast. It's the same bars that are faint in every mode.

Any help much appreciated,
Thanks,
 
If just few segmenst are bad, it could be a bad contact.

If all the display is like that, I would check power supply to it.

Rudolf

"Derek" <joe@hotmail.com> wrote in message
news:p4ll80pb6h9j2r08dpetogkbvu6f9ekm4v@4ax.com...
Before I start, I have tried a Google search, and no luck.

I have a digital, hand-held tachometer for checking the r.p.m.s of
"stuff". I can read the display, but certain bars of the display are
very faint and I must play with the angle to see the numbers.

My question is this, is this (usually) a degradation of the display
itself, or is it something like poor contacts inside? I know this is a
vauge question, but any help would be appreciated. I have opened the
unit and tried re-seated everything, but I'm nervous to go too far. I
have done the obvious like replacing the battery and adjusting the
contrast. It's the same bars that are faint in every mode.

Any help much appreciated,
Thanks,
Click to expand...
 
On Sat, 24 Apr 2004 14:17:54 -0700, Derek <joe@hotmail.com> wrote:

Before I start, I have tried a Google search, and no luck.

I have a digital, hand-held tachometer for checking the r.p.m.s of
"stuff". I can read the display, but certain bars of the display are
very faint and I must play with the angle to see the numbers.

My question is this, is this (usually) a degradation of the display
itself, or is it something like poor contacts inside? I know this is a
vauge question, but any help would be appreciated. I have opened the
unit and tried re-seated everything, but I'm nervous to go too far. I
have done the obvious like replacing the battery and adjusting the
contrast. It's the same bars that are faint in every mode.
Click to expand...
IMOE degradation of LCD's manifests itself across segment most used if it
results from a significant DC drive component. Otherwise, evenly across all
segments if it results from aging/high_temp.

Most likely though it is the result of poor contact on the zebra strip.

Made the mistake once (yep, I learned) of opening a Fluke DMM at work that had a
virtually undetectable display. Reseated the LCD on the zebra and it was like
new, but *they* saw the result and it didn't make it to the bin :-(
 
On Sun, 25 Apr 2004 15:10:54 +0800, budgie <me@privacy.net> wrote:

On Sat, 24 Apr 2004 14:17:54 -0700, Derek <joe@hotmail.com> wrote:

Before I start, I have tried a Google search, and no luck.

I have a digital, hand-held tachometer for checking the r.p.m.s of
"stuff". I can read the display, but certain bars of the display are
very faint and I must play with the angle to see the numbers.

My question is this, is this (usually) a degradation of the display
itself, or is it something like poor contacts inside? I know this is a
vauge question, but any help would be appreciated. I have opened the
unit and tried re-seated everything, but I'm nervous to go too far. I
have done the obvious like replacing the battery and adjusting the
contrast. It's the same bars that are faint in every mode.

IMOE degradation of LCD's manifests itself across segment most used if it
results from a significant DC drive component. Otherwise, evenly across all
segments if it results from aging/high_temp.

Most likely though it is the result of poor contact on the zebra strip.

Made the mistake once (yep, I learned) of opening a Fluke DMM at work that had a
virtually undetectable display. Reseated the LCD on the zebra and it was like
new, but *they* saw the result and it didn't make it to the bin :-(
Click to expand...
Thanks for the input guys. Sorry you didn't score a Fluke DMM!!!

I'm pondering..."If it aint broke....don't fix it". I'd really like to
have all segments at the same contrast, but would hate to have it end
up in the bin. Problem is, after I few beers, I have enough Dutch
Courage to want to attempt the repair, but fear the groggy
concequences. Without a few beers, reason (which I hate) kicks in and
says, leave it be! I've abused cheap calculator LCDs' in the past,
with no ill effects. Knowing my luck, this will be the one time the
wheels fall off! ....Oh well.

Thanks.
 
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