Author Topic: Fluke 87 IV broken sockets repair/cleaning questions  (Read 978 times)

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Offline wasteTopic starter

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Fluke 87 IV broken sockets repair/cleaning questions
« on: April 03, 2022, 09:38:21 am »
Well I went to my local dump to throw some electro-garbage and glaring in front of me there was a fluke 87 IV.

I took it home and tried to troubleshoot it . The usual protective resistors/MOVs read quite well , apart from one MOV which reads 14MΩ (do I need to replace that? I will try to check on it later). That is the MOV
https://www.eevblog.com/forum/repair/fluke-179-need-help-identifying-part/

But my main issue is that the voltage socket is having a bad connection sometimes reading 2-4MΩ and sometimes it makes a good contact. I tried cleaning them very well with IPA like here
http://mrmodemhead.com/blog/gallery/fluke-189-clean-up/

It helped with the one lead inside, but not with the second on the other side which still reads 2-4ΜΩ. And of course the meter cannot get good readings to further test, because the resistance from the lead to the board jumps from 3ΜΩ to 0 all over.

 Can I do something to fix this issue? Can I find a similar socket?


« Last Edit: April 04, 2022, 05:59:22 pm by waste »
 

Offline Shock

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Re: Fluke 87 IV repair/cleaning questions
« Reply #1 on: April 03, 2022, 01:39:16 pm »
Firstly clean them really well, the sockets get all kind of gummed up and typically you think they are clean but they aren't. Then if you are still experiencing issues you can measure the resistance with another meter from an inserted cable to the terminals at the back to ensure good conductivity/low resistance. Don't use the meter to measure itself and obviously remove the battery etc when working on it.

Sockets can still be purchased on ebay, if it's that.
Soldering/Rework: Pace ADS200, Pace MBT350
Multimeters: Fluke 189, 87V, 117, 112   >>> WANTED STUFF <<<
Oszilloskopen: Lecroy 9314, Phillips PM3065, Tektronix 2215a, 314
 

Offline wasteTopic starter

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Re: Fluke 87 IV repair/cleaning questions
« Reply #2 on: April 03, 2022, 02:46:19 pm »
I cleaned them well until the earbud was completely free of muck.
And of course I did all measurments from another multimeter

I even try to resolder them now and I discovered that the one pin of the two goes around freely when it's hot from the solder, so it looks like a broken connection.

But I couldn't find sockets on ebay, maybe Im searching for the wrong term (banana sockets?).


seems Im not the only one with this kind of problem
http://mrmodemhead.com/blog/fluke-80-series-jack-assembly-rebuild/

Quite a common issue,
The Fluke part number is 89-4-8002

Does anybody know a cheap source of these in europe?? Cheapest I found was 40euros including shipping :)
« Last Edit: April 03, 2022, 03:18:57 pm by waste »
 

Offline alm

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Re: Fluke 87 IV repair/cleaning questions
« Reply #3 on: April 03, 2022, 03:01:43 pm »
The loose connector doesn't happen to be related to the jack sensing that's used for the alert if you have the leads in the wrong jacks for the currently selected function (current or voltage)? Although I wouldn't expect those to be loose either.

There's these input terminals for the 87-III and 87-V series, but I don't think it would fit the 87-IV. You can compare the pictures, though.

Check the service manual if the part number matches that of the 189, which has been in production for longer and more recently. Then try asking Fluke if this is still a current spare part they sell. You might have to ask an official distributor of Fluke to order the part for you. I don't think Fluke sells parts directly in Europe.
 
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Offline wasteTopic starter

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Re: Fluke 87 IV repair/cleaning questions
« Reply #4 on: April 04, 2022, 05:58:23 pm »
mA A sockets are ok (probably they haven't seen much use). It's the voltage one and the common who are problematic .

the 87-iv shares the same socket with 187 189 series but I can't find them for less than 40 euros around here which I consider ridiculous for such a part. So my current strategy is to turn them around and use the ma A sockets for V and common and repair the broken ones with messing pipe.

After all I didn't use the messing pipe as Mrmodemhead did (even though I took a lot of courage from his work, here http://mrmodemhead.com/blog/fluke-80-series-jack-assembly-rebuild/#comment-231595).

 I decided to use the old broken pieces and attach new leads. This was partly because in euroland we have only 4-6mm (OD) which doesn't fit our 4mm (ID) sockets.

So I took out the broken parts, (4mm-4,5mm drill in the center to take the plastic out only 5mm deep is enough).  I soldered pieces of wire on them and filed down the outer part to be smooth.

Then I inserted it back in the plastic (it has a guide so it is easy if you dont drill too deep). I put a small 3d printed cylinder of 3,5mm to keep the distance (not sure if it was necessary) and then epoxied the whole thing.


As I don't know how long my handwork will last, I soldered the sockets the other way around. So the repaired sockets stand on the mA and A side, and the non broken ones on the Volt/common. Works pretty well, as now-a-days I usually use the clamp meter for the Ammeter .


PS should I change the title of the thread to reflect the repair part?
 


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