Need help repair FLUKE 867B

[Vedran]

Hi there,

I'm new member to your community and I'm glad that I've found you guys.

I have FLUKE 867B and half of it's features doesn't work. When I select LOGIC, Component test, SET UP, ~V, V I get nothing on display (Image attached).

When I select mV, Ohm, diode, mA or A everything works fine. Display is showing everything and I can do measurements (Image attached).

I have found Manual on this link:
http://monitor.espec.ws/files/service_206.pdf

I have disassemble it two times until now and I tried to clean contacts and check one relay but it all works fine. Can you please tell me is there anything I can do or what component to check inside? Thank you very much for any help.

[Jacek_Paw]

On one side of the board under the knob slider you can find black coated (probably with carbon) pads. Basing on the slider position over the pads the meter determines the selected function if there is a problem with contact none function is selected.

Try to clean the pads with IPA or maybe even try  to scrub (gently and carefully) them a bit with thin sandpaper.

In my unit the described method solved identical problem.

[Vedran]

Thank you Jacek for your replay   . It works now for AC and DC like a charm!!! SET UP and COMPONENT TEST doesn't work but I don't care!

I did this cleaning for three times and it didn't work. Now I've disassemble contact all together from PCB. Scrub little harder with sandpaper and small screwdriver (only for metal parts) and even found hidden metal contact plate under plastic ring (Image attached).

Thank you very much for your time!

[retiredcaps]

Your problem is very similar to these two modemhead blog entries.

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

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

[harrimansat]

I had the same problem, today I have seen that the fault is connection between confuctive carbon pad and copper, 500ohms aprox. If you make some pressure it works again, this explain why when I clean it works for a while. I have put some silver conductive paint and now it works.

[nedsim]

I know this is an old thread, but wanted to add my nod to the tips offered up. I picked up an 867 that would not enter any of the modes on the left of the dial. Cleaning the selector switch contacts solved my problems as well. Used an acid brush with the bristles trimmed short and isopropyl to gently scrub the carbon pads on the PCB. Strips of copy paper with a drop of isopropyl  inserted between the contact fingers cleaned them up. And thanks for the mention of the contact on the back of the wafer that's visible thru the hole. All in all, pretty easy.