I have a Fluke 105 Series 2 Scopemeter whose lcd has become really
faint. I have tried cleaning the pcb contacts to the lcd. (Three zebra
strips connect the lcd to the pcb) and have also removed the zebra
strip and cleaned the lcd glass contacts, but this has not made any
difference.

Any suggestions on what could be wrong? Do Lcd's go bad after some
use??

Thanks
Jay

Is this a portable LCD scope/DMM? Tried fresh batteries? Some LCD's use a
polarized filter in front of the glass, if that is gone it will make it hard
to read.

"jay" wrote in message
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I have a Fluke 105 Series 2 Scopemeter whose lcd has become really
faint. I have tried cleaning the pcb contacts to the lcd. (Three zebra
strips connect the lcd to the pcb) and have also removed the zebra
strip and cleaned the lcd glass contacts, but this has not made any
difference.

Any suggestions on what could be wrong? Do Lcd's go bad after some
use??

Thanks
Jay

Hi Michael,

Thanks for the response. It's a portable scope, yes I have replaced the
batteries and also tried powering it directly from the AC adapter but
same results.

Since the entire display exhibits fading I think I can rule out the
elastomer connectors being the issue.

You might be on to something WRT the polarized filter. Anyway to
replace that? When I removed the lcd I could not really open up the
front of the lcd so not sure if the polarized filter could be removed
easily. What is the failure mode for the polarized filters. Do they go
bad with heat or moisture etc?

Thanks
Jay

jay wrote:
Hi Michael,

Thanks for the response. It's a portable scope, yes I have replaced the
batteries and also tried powering it directly from the AC adapter but
same results.

Since the entire display exhibits fading I think I can rule out the
elastomer connectors being the issue.

You might be on to something WRT the polarized filter. Anyway to
replace that? When I removed the lcd I could not really open up the
front of the lcd so not sure if the polarized filter could be removed
easily. What is the failure mode for the polarized filters. Do they go
bad with heat or moisture etc?

Thanks
Jay



Are you sure there isn't a contrast adjustment anywhere? Most monochrome
LCD graphics displays have one.

There is a contrast adjustment but tweaking it just makes the whole
screen darker still does not make the lettering any darker I have
emailed fluke now to see if they respond

jay wrote:
There is a contrast adjustment but tweaking it just makes the whole
screen darker still does not make the lettering any darker I have
emailed fluke now to see if they respond



I suspect there's a problem in the driver circuitry, perhaps the power
supply for the display. Personally I would send it away to Fluke for
repair, they'll calibrate it in the process.