FLUKE 87 III shematic diagram

[MBfreak]

Hello to all.
My FLUKE 87 III is showing very wrong on the mA AC and DC range.
Just happened, no magic smoke or overload .
On microA and A all is well , also all other functions are correct.
I have not overloaded the input circuit and fuses are correct.
When measuring the shunt values thru the COM, mA/microA and A sockets shunt values are exactly the same as on a known good FLUKE 87 III.

Have tried to locate a schematic diagram, but no luck.

Can anybody please help with a link to any FLUKE 87 or 177 DVM?

Thanks a lot

Ola

 

[M10]

http://assets.fluke.com/manuals/8xiii___sieng0200.pdf

 

[wyliesdiesels]

how old is it?

Maybe send it to Fluke for checkup and calibration?

 

[MBfreak]

M10.
Thanks for the manual! Will be of some help.
Wylis
After 60 years of working with a wide range of technology ( from nuclear power stations to bicycles) , both as a job and for hobby, I am not much interested in sending private stuff out for repair.
Repairing my own tools, cars, appliances, electronics is an excellent lesson in actually trying to understand things in detail, test my knowledge and perseverance.I get satisfaction from the actual repair.
When I fail, I just start over with a more humble attitude, which very often helps.

Matthew B Crawford has an excellent book on this subject " Shop Class as Soul Craft"

Best regards

Ola

 

[gungatim]

that is a great book, I picked it up and read it a few years ago when someone on here recommended it...good luck with the Fluke...

 

[Citation]

Hello to all.
My FLUKE 87 III is showing very wrong on the mA AC and DC range.
Just happened, no magic smoke or overload .
On microA and A all is well , also all other functions are correct.
I have not overloaded the input circuit and fuses are correct.
When measuring the shunt values thru the COM, mA/microA and A sockets shunt values are exactly the same as on a known good FLUKE 87 III.

Have tried to locate a schematic diagram, but no luck.

Can anybody please help with a link to any FLUKE 87 or 177 DVM?

Thanks a lot

Ola

I'm pretty sure only the 87-1 service manual is on the web. You might check out the EEV blog forum. MrModemhead may be able to help. He also had a blog with lots of good information. A failure in the mA range could be a number of things related to the safety circuits. Just to make sure, was the meter, in particular the switch, disassembled?

 

[SIX225]

I know it sounds super obvious, but did you change the battery? My Fluke at work was giving some crazy readings one day and a couple days latter the battery indicator went on.

 

[MBfreak]

The Fluke is back in service.
Thanks to a schematic diagram ( actually a whole book with complete descriptions of everything in a Fluke 87, + 100 pages, very detailed ) I saw that the input jacks were split in two separate parts and connected together when a test lead is pushed in.
The last time I used the Fluke was on a lathe with loads of electronics.
A chip , like a small spring, had managed to jump in and connected the two halves in the input jack ! This screwed up the mA readings!

So all is well, will make plastic plugs to cover the inputs not in use!

Ola

 

[W-Cummins]

The Fluke is back in service.
Thanks to a schematic diagram ( actually a whole book with complete descriptions of everything in a Fluke 87, + 100 pages, very detailed )

Ola

Glad your back in service! Where did you get the manual your describing above The fluke link is only 30 pages and not any schematics:-(




thanks


William......

 

[MBfreak]

W Cummins.
PM me with your email, I´ll send you the complete manual-
Would not load here.

Ola