My Fluke Scopemeter 91 series 2 had 4 keys that were not functioning. The cause of this is usually the membrane under the keys that has worn out.

Supplies

Fluke Scopemeter 91,96 Series 2 keypad membrane: Ebay

Tools:

1) Torx screwdriver with assorted sizes.

2) Philips screwdriver with assorted sizes.

3) Small flat screwdriver

4) Small long nosed pliers.

Step 1: Disassembly

Remove two torx screws from back of battery compartment, remove the battery door which you can pry off with a flat blade screwdriver. Remove the battery from compartment.

Step 2: Remove the End Cap.

Remove the end cap by removing the two screws. Once the end cap is removed, the two halves of the meter come apart. Take apart very carefully as there is a ribbon cable connecting the two boards inside the meter.

Step 3: Seperate the Two Halves of the Meter.

Gently separate the two halves of the meter and gently set flat without damaging the ribbon cable. The left-hand circuit board can then be removed by removing the two torx screws in the middle and the two phillips screws on the bottom.

Step 4: Lift Up Circuit Board, Replace Membrane and Re-assemble Meter.

Raise the left-hand circuit board gently and replace the keypad underneath. Refer to Youtube video for in depth instructions on how to replace key pad membrane and how to re-assemble meter.