Fluke 87 going south?!

[Aikiotto]

Hello All

Lately my old Fluke 87 have been behaving erratically , display fading, eating batteries in matter of days , measures going up/down constantly even without leads even connected and the like.

Since this is a very old meter , i was thinking wheter it was worth or not to have it repaired/serviced/calibrated , a call to a representative yielded a quote of about 100$ plus S/H.

So what would you guys suggest? a new tester? wich one would be better suited for light use in laptop/lcd troubleshouting wich i've started to get into recently?, or should i just repair the old one?.

Ive considered getting the Blue ESR meter , so in case you suggest a good one what specs should i look for that would be a good complement for the esr meter?

Your insights are very appreciated , thanks in advance
Aiki

[Krankshaft]

The display fading issue can be solved by replacing the zebra strip on the back of the display. Fluke has a kit available with a new one.

Ignore the instructions to wipe the old one with a pencil eraser the effects are short lived and the display will begin to fade again.

Is it possible the segments of the display are dropping out due to the bad zebra strip and you are misinterpreting that as a fluctuating reading?

The Fluke 87 series is a good meter and based on what it cost new it would be worth a repair. If your issue is only a fading display you can do it yourself easily.

If you wanted to upgrade to the newer 87-5 it cost me around $280 and that was the lowest price I could find. So you have to weigh whether the added features and the higher cost for a new unit are worth it.

One things for sure there's no way you're going to get a better meter for the $100 repair fee.

[Aikiotto]

Hey Krankshaft

I did read about the kits for the lcd from ebay (some 28$) and if it only were that issue i would not have doubts about solving , but im not 100% sure if thats the problem , since with new batteries the screen works perfectly....if only for a few days before it indicates low batt again.

But even with a new batt I just switch to mDC measure for instance , it just start showing values out of nothing going up and down with no leads plugged , it also kind of turns on and shut off by itself for half a second if i hold to it tight and things like that.

I checked the 87-5 its going for some 320$ at amazon wichs a bit steep considering how seldom im using it atm , so i tought about hearing opinions on others DMMs like the Fluke 115 (129$ at amazon) or any other brand/models you know about.

[retiredcaps]

Originally Posted by Aikiotto

but im not 100% sure if thats the problem , since with new batteries the screen works perfectly....if only for a few days before it indicates low batt again.

1) I haven't taken apart a Fluke 87 (I don't have one), but I do recall do some research on multimeters and ran into a couple of posts that might help?

2) First is carbon contacts causing smears that drain the battery.

http://www.eevblog.com/2010/02/08/ee.../#comment-5956

3) Second is cleaning the contacts

http://www.audiokarma.org/forums/sho...d.php?t=123354

4) I guess you can also verify a parasitic drain by hooking up another multimeter and checking the amps draw while the Fluke 87 is turned off. Sort of like a car battery parasitic drain test.

5) If none of this helps and you are considering buying a new one, PM me regarding your old Fluke 87.

6) Don't forget about ebay. You can get some brand new Flukes for less money. I have seen the 117 go for about $100. Sometimes a 177 as well for $100.

I believe the 11x series are all made in China. I think the 17x is made in the USA. Dave Jones at eevblog reviewed the 117 and found the made in China just as good as made in USA. See

www.youtube.com/watch?v=3k9nVg03Wi4

[Aikiotto]

Thanks for the links Retired

Whats described in the EEV blog from your link seems like exactly the problem with my unit , wich is the rotary switch wonder if thats servicable by a newbie.

Do you think the meter would lose calibration somehow if i were to try and clean those carbon contacts? and whats the safest product to use for such a task?.

Thanks again

[retiredcaps]

Originally Posted by Aikiotto

Whats described in the EEV blog from your link seems like exactly the problem with my unit , wich is the rotary switch wonder if thats servicable by a newbie.

Service manual is at

http://www.ko4bb.com/Manuals/Fluke/M...ice_Manual.pdf

See chapter 3. It has disassembly instructions and how to clean the rotary switch (section 3-12).

Do you think the meter would lose calibration somehow if i were to try and clean those carbon contacts? and whats the safest product to use for such a task?.

As long as you don't touch R21, R34, C2, C3, and C37 (section 3-29), you shouldn't affect any calibration settings. Don't even breathe in that direction!

Section 3-12 has suggested cleaning tips and materials.

I would like to ask a favour. Since I don't have a Fluke 87, can you please take pictures of the step by step process so I can "virtually" repair this? I have a huge interest in multimeters.

Please use the manage attachment feature to upload your pics and please don't post inline for my sake.

[smason]

It's absolutely worth fixing, especially since you can do it yourself.
I'd definietly replace the elastomer on the display, and clean the switch, bet that's all it needs.

[cadiman]

These meters are very easy to take apart.

I have an old 87 and every once in a while I take it apart and clean it and do some re- soldering. I have installed circuit breaker in place of the fuses.
(tired of replacing expensive fuses)

I drop it alot and subject it to cold and hot conditions all the time.

This is the best meter I have ever had and I bought it used for 120.00

It is worth fixing.

Start with a good quality battery and a good cleaning.

Make sure you are using good test leads too.

[retiredcaps]

Originally Posted by cadiman

I have an old 87 and every once in a while I take it apart and clean it and do some re- soldering.

May I ask what parts are you resoldering? I'm thinking about getting a used Fluke 87 and just want to know if I have to be doing the same.

How has your calibration held up over the years?

I have installed circuit breaker in place of the fuses.
(tired of replacing expensive fuses)

I have purchased 2 used Flukes and both times the seller did not disclose that the milliamp fuse was blown.

Now I'm baffled why these milliamp fuses are blown for the following reason. If someone can spend the money to buy a Fluke, then I'm assuming that person is an experienced multimeter user which implies always testing the circuit on the highest Amp rating first (usually 10A). If the amp reading is comfortably lower than the rated multimeter milliamp scale, then and only then, move the probe to the milliamp scale to get better resolution.

I can see inexperienced users blowing out the fuse, if there is one, on the cheap 830 multimeter ebay variations, but not someone spending $400 on a Fluke 87-V.

Similary, if you even think the circuit is more than 10A, then I would expect an experienced user to get out their amp clamp and use that.

[smason]

I can't imagine a Fluke needing any soldering unless you toasted a compnent that needs replacing. Build quality (and soldering) have always been really good on any FLuke I've had apart.

[KeriJane]

+1 vote for careful disassembly, inspection and cleaning.

Be careful with replacing those expensive fuses with any kind of substitute.

If I recall, those expensive Fluke fuses are designed to prevent high-voltage arcing which can happen with a regular fuse or circuit breaker.

If, for example, one left the meter on an Amps setting and accidentally probed a 440v line the circuit breaker or "plain" fuse would immediately blow and prevent damage, right?

Wrong!

The fuse will blow but the high voltage can continue arcing through the space opened by the melted link and would most likely cause severe damage to the meter and user.

Ow.

Those expensive fuses are designed to minimize that risk.

If your meter uses the cheaper fuses or has been modded in any way it is best to label it clearly "LOW VOLTAGE ONLY" and then make sure that absolutely nobody else borrows it for anything, ever.

Or better, just get "those darn expensive fuses" and learn to stop making them pop.

[Agent24]

Are those "zebra stripe" LCD connectors a universal thing that can be obtained easily?

I've got a couple of handheld games with a fading display problem. Both use those strip connectors.

[budm]

@retiredcaps, I have about 6 of these 87 at works, what happen is that when you want to measure the current, you have to move the red probe over one of the two fused current inputs, one is for 400mA max, another one is for 10A max, if the person forget to move the red probe back to the V/Ohm input and use it to measure voltage, boom!, it blows the fuse.
I also order spare 4-input jack assemblies, what happen is that the contacts inside just worn out, or sometime crack solder joints on the jack to the PCB. It is great meter, I use it at home also.
Regular fuse only has 250v break down, not recommend if you are going to hand this meter out to your employees without having proper type of fuse installed.

[retiredcaps]

Originally Posted by budm

@retiredcaps, I have about 6 of these 87 at works, what happen is that when you want to measure the current, you have to move the red probe over one of the two fused current inputs, one is for 400mA max, another one is for 10A max, if the person forget to move the red probe back to the V/Ohm input and use it to measure voltage, boom!, it blows the fuse.

One of the features of the Fluke 87 is the input alert. According to page 1 (one) of the manual ...

"An Input Alert (tm) that causes the beeper to sound if the test leads are plugged into the wrong input terminals for the function being performed."

So unless people aren't paying attention, the beeping should alert them to something wrong and they should double check their input jacks.

Some newer multimeters now have a shutter to close off the input jacks depending on the selected rotary setting. Others now prominently flash "LEAD" on the display.

It wouldn't be so bad, but Fluke fuses are $6 to $8 each. At that price, you guys should get the Harbour Freight $4 multimeter specials and use them exclusively for current measurement.

[budm]

Sometime the areas are very noisy and the users do not pay attention so it happens.
My work place required yearly calibration certificates for all of our test equipment since we are UL and CSA certified labs, cheap meters will not make it.

[retiredcaps]

Originally Posted by budm

My work place required yearly calibration certificates for all of our test equipment since we are UL and CSA certified labs, cheap meters will not make it.

Well stock up on the fuses then. I have purchased 3 used multimeters and each one has the milliamp fuse blown, but the sellers never disclosed that little fact.

I don't mind paying for one Fluke 440ma replacement fuse because I'm confident that I will highly unlikely to blow it, but the shipping from digikey.ca is a minimum of $8 and ebay Fluke fuse sellers want $15 for shipping and handling for a fuse!!!

[budm]

We do stock them up, part of doing business. I do not want to tell you how much it costs us each year to have our equipment calibrated.
We just bought new scope for $80K, probes are OPTIONS!
UL, CSA, TuV for our products compliance testing are even worst.

[retiredcaps]

Originally Posted by budm

We do stock them up, part of doing business. I do not want to tell you how much it costs us each year to have our equipment calibrated.

Part of me really wants, but does not need, a Fluke 87V. The only problem with buying an used Fluke 87V is I'm worried about its calibration (or lack of it). As I understand it, you need special software and calibrator to get it done since the 87V is closed case calibration.

The original Fluke 87 and 87III had potentiometers so you could DIY if you had an accurate source.

I recently bought an older pocket multimeter off ebay. The AC and DC readings were well off compared to my Fluke. I opened it up and found two pots. I figured out which was DC and I tuned it so now it reads similar to the Fluke.

I also got an old Micronta multimeter for free and its accuracy was well off too. I had to tweak the pots.

Let's hope my Fluke is accurate!

I understand that software driven closed case calibration is probably more reliable and accurate than turning a screwdriver on a pot even at a calibration lab.

Obviously, this is all for my home/personal use which is "good enough".

[Aikiotto]

Hello and sorry for the late update , buts been a crazy couple of months!!

I finally got an used 87-V off Amazon (on the mail atm from the US to where im in Venezuela) with an industrial probes set , carrying case and whatnot for some 250$ , as for my old 87 i managed to clean the contacts on the rotary switch with pure alcohol and didnt exhibit the issue for a couple days , then its back to misbehaving.

Once the new baby arrives i hope you guys can help me check its calibration , an issue retiredcaps just got me thinking about lol.

Thanks for the help!

[retiredcaps]

Originally Posted by Aikiotto

as for my old 87 i managed to clean the contacts on the rotary switch with pure alcohol and didnt exhibit the issue for a couple days , then its back to misbehaving.

If misbehaving means the battery is dead, then I suggest you use your 87V to measure the current drain when the 87 when it is off.

I'll post pictures later, but this is an easy test to do to see if your Fluke 87 is consuming battery when it is supposed to be off.

I used my Fluke 27 to measure the current consumption of my Fluke 83III. For most ranges, the Fluke 83III consumed roughly 0.840 ma. With the backlight on, it jumped to 25ma. When turned completely off, the Fluke 83III consumed 0.0ma (as expected).

Once the new baby arrives i hope you guys can help me check its calibration , an issue retiredcaps just got me thinking about lol.

I have now purchased several used Flukes from various parts of the world in various conditions. All of them are within 1 millivolt of each other when measuring DC voltage. I have also purchased non Flukes and all 4 of them were well off (one was 1% off) wrt to DC voltage.