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what is the best way to go about fixing a bad LCD led segment

E

Eric Lada

Jan 1, 1970
0
Hello!

I have a small handy talky radio that has a bad LCD segment. Does
anyone have any starting points / tips / pointers for repairing the
segmented LCD displays, or know how they ussually break.

-Thanks!
 
S

Sam Goldwasser

Jan 1, 1970
0
Eric Lada said:
I have a small handy talky radio that has a bad LCD segment. Does
anyone have any starting points / tips / pointers for repairing the
segmented LCD displays, or know how they ussually break.

Bad connections. For an LCD, probably just need to clean the Zebra stripe
elastomer pads going to the LCD panel. Else, may be bad solder connections.

The driver chip could be bad but that's a lot less likely.

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.
 
L

Lynn Coffelt

Jan 1, 1970
0
"Eric Lada" .> wrote in message > I have a small handy talky radio that
has a bad LCD segment. Does
anyone have any starting points / tips / pointers for repairing the
segmented LCD displays, or know how they ussually break.
Repair is not for the faint hearted, but:
Over the period of quite a few years, the most common segment failure
I've encountered has been a failed connection right at the back of the LCD
glass surface. I cannot become enthusiastic about telling anyone to try
this, but it has worked for me probably a hundred times.
There are several methods used to make the electrical connection to the
glass surface. One that is easiest to repair is the one that uses a
conductive rubberlike strip sandwiched between the display driver part of
the PCB and the LCD's rear glass surface.
For some reason, the actual electrical resistance between this
rubberlike strip and the glass becomes too high. It is quite often corrected
by a simple cleaning of the glass, rubberlike strip and the PCB lands the
strip touches. My best luck cleaning has been with a "Q-Tip" slightly
moistened with very high percentage pure alcohol. Beer or vodka are not good
choices.
All that secret technical information above is only useful if you are
able to disassemble the LCD's mounting assembly and get it back together
successfully. Manufacturers have not made this easy in most cases, and
success or failure will most likely depend on someone's ability to carefully
disassemble and reassemble the little bugger.
If you have a tendency to drop small screws, or sneeze while working,
maybe just living with the missing segment is best.
Old Chief Lynn
 
J

jakdedert

Jan 1, 1970
0
Lynn said:
"Eric Lada" .> wrote in message > I have a small handy talky radio that
has a bad LCD segment. Does


Repair is not for the faint hearted, but:
Over the period of quite a few years, the most common segment failure
I've encountered has been a failed connection right at the back of the LCD
glass surface. I cannot become enthusiastic about telling anyone to try
this, but it has worked for me probably a hundred times.
There are several methods used to make the electrical connection to the
glass surface. One that is easiest to repair is the one that uses a
conductive rubberlike strip sandwiched between the display driver part of
the PCB and the LCD's rear glass surface.
For some reason, the actual electrical resistance between this
rubberlike strip and the glass becomes too high. It is quite often corrected
by a simple cleaning of the glass, rubberlike strip and the PCB lands the
strip touches. My best luck cleaning has been with a "Q-Tip" slightly
moistened with very high percentage pure alcohol. Beer or vodka are not good
choices.
All that secret technical information above is only useful if you are
able to disassemble the LCD's mounting assembly and get it back together
successfully. Manufacturers have not made this easy in most cases, and
success or failure will most likely depend on someone's ability to carefully
disassemble and reassemble the little bugger.
If you have a tendency to drop small screws, or sneeze while working,
maybe just living with the missing segment is best.
Old Chief Lynn
I've done some repairs as you describe; but my old Nokia 51xx/61xx
series phones had a similar problem that was much easier to repair.

The display--the entire unit--was simply a pressure fit in the case.
With proper disassembly of the case, the whole thing would fall out of
the phone, as it was only connected to the circuit board by spring
pressure on the contacts.

Many of those phones (I had at least a dozen over time) were fixed by
merely cleaning up the contacts on the board and LCD unit, and
retweaking the springs.

Hopefully the OP's unit could have something similar....

jak
 
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