FWIW, I've got a Fluke 77 that I bought in the late '80s. no such problems.
I do have to change the battery about every four years.

In my experience, a dim LCD is usually indicative of low power supply voltage.
Though what's strange here is that that shouldn't vary with the function being
displayed. Anyway, I'd check connections several times before ripping into
anything.


"Jack Erbes" wrote in message ...
Gary wrote:
I have a Robertson AP3000X on my boat. The J-box (brain) was replaced last
year due to corrosion on the circuit boards. Last weekend, I was using the
boat and noticed that the LCD control head seemed to be displaying the
information very dimly. snip

I have a Fluke multimeter (67? 77?) that has a LCD display that fades out every two years or so. If I open the case and remove
the plastic frame that holds the display there is a sort of gray and pink rubbery or felt like looking strip on the bottom of
that. That strip makes contact with a row of brass contacts on the PCB. The rubbery/felt strip and the contacts on the PCB are
the contact points for activating the LCD display segments.

If I take a Q-tip, wet it with isopropyl alcohol, and gently clean the rubbery looking strip and the brass contact patches on the
PCB I have a like new black on gray LCD display.

This process has saved me from wanting to buy a new Fluke about every two years over the last ten years or so.

I wonder if you could be having a similar problem?

Jack

--
Jack Erbes in Ellsworth, Maine, USA (jackerbes at adelphia dot net)
(also receiving email at jacker at midmaine dot com)