Fluke 88 Flickering and Staying on

[hpmaxim]

I have what seems like a weird problem with a Fluke 88 (I suspect this is pretty similar to the Fluke 87).  The display (and sometimes the backlight) will flicker on/off when I rotate the selector knob.  In some cases, it'll actually stay on when in the off position.  It usually settles down pretty quickly when you take your hand off the knob, but occasionally you have to physically poke at or tweak the knob a bit to get it to actually shut off.  Any idea what the cause is or how to correct it? 

[retiredcaps]

Dirty tracks on range switch?

http://mrmodemhead.com/blog/fluke-83-dmm-repair/

http://mrmodemhead.com/blog/fluke-83-iii-rotary-switch/

Lots of other ideas on his site as well as the 2 above.

[hpmaxim]

[hpmaxim]

It looked very different than described.  The backside seems to be the PTF layer they described.  However I saw no white disc, it was just that thing on the front.  It looked like there was a plastic/metal disc but I couldn't get it clear of the assembly to get it out.  Maybe I could have but it looked like it would be easy to damage if I tried to force it.  I was able to get some dirt off the front but it's not clear that I got anything off the back.  I cleaned it with isopropyl as stated.

The black disc on the back doesn't want to go back on -- and I'm not sure how it's supposed to be aligned (not that I can even get it in).  I took it off with popsicle sticks, and it just kind of flew off.  Looks undamaged but still won't go back on.

Any ideas?

[hpmaxim]

Key to the mystery was: "I took it off with popsicle sticks and it just kind of flew off."  Apparently, there was another little plastic piece that went through the center that also went flying and that I didn't see.  Found it on the ground next to me and was able to get everything back together pretty easily.  Seems like it's fixed now.  Who knows for how long.