Fluke 85-3

[mzacharias]

Wondering if anyone here has had similar issues with a 80 series III Fluke. Primarily the problem is excessive current drain in "sleep" mode.

My 85-3 is five years old, purchased new from MCM in the U.S. Current drain in normal operation is around 820uA. In so-called "sleep" mode (auto power-off) it only drops to about 780uA. In other words, a battery hog unless you turn it off physically.

Even so, it actually pulls 9uA even with the switch OFF!

Otherwise, operation seems normal. I sent it in for factory service; hopefully they'll get it right - I have no experience with Fluke service.

BTW, talking with a Customer Service Rep implied that contrary to their stated policy, if one of these is returned for service and has not been abused, they will fix it free, not just for the original purchaser from an authorized dealer. I would suggest just don't mention eBay...


Mark Z.

[EEVblog]

I recall someone saying it's possibly due to leakage between the switch contacts?

Dave.

[Kiriakos-GR]

Where is actually the DMM at the moment ?  
Is it at the Fluke " hands " ?

[mzacharias]

I shipped it to Fluke yesterday. Maybe about one week before I really hear anything.

[Kiriakos-GR]

Ok , if so , 
you will have to wait ,  test it after it arrives , so to verify how it behaves , and report back.

[mzacharias]

I recall someone saying it's possibly due to leakage between the switch contacts?

Dave.

If it's the switch, it's been bad since day one, as the problem has existed since then. I just didn't recognize it was improper operation at the time.

Mark Z.

[Kiriakos-GR]

Fluke will do all tests , and repair if needed ..

I like to believe that when it will be back , it should behave as an  healthy one .

By testing it , you will find out , if the cure worked out , if not could be an specific model issue. 

[Excavatoree]

Interesting, I measure approximately 9 uA in "off mode" of my 87-III that I have here at work.

(Not sure what the specs are for the 25 I was using to measure the current.  I need a microcurrent adaptor.)

The last time I looked at the schematic for an 87 (old "no series" and "series 3") I seem to remember that the power switch doesn't disconnect the battery, it's just a signal. (This brings up Dave's point of why there couldn't have been a separate button.)

The -5 is a different architecture.

[mzacharias]

Interesting, I measure approximately 9 uA in "off mode" of my 87-III that I have here at work.

(Not sure what the specs are for the 25 I was using to measure the current.  I need a microcurrent adaptor.)

The last time I looked at the schematic for an 87 (old "no series" and "series 3") I seem to remember that the power switch doesn't disconnect the battery, it's just a signal. (This brings up Dave's point of why there couldn't have been a separate button.)

The -5 is a different architecture.

Interesting. OK, I'll accept that the 9uA in "OFF" mode is normal. That's good information, and not a fatal flaw in terms of battery usage.

Hopefully Fluke will fix the excess consumption in sleep mode, and I'll be happy.

[mzacharias]

Update on the Fluke 85-3:
Fluke received it, put a battery in it, let it run over a weekend, and decided it was OK. Didn't even test the auto power-off function, not until I called them back on it and straightened them out. They put it back in the repair queue. Still waiting to hear from them again.
They said they never even had a current meter on it, and yet said it consumed 1.29mA in normal operation.
Hmmm. Those are 87-5 numbers. Methinks they were just pulling numbers out of their a**. The 85-3 uses about 820uA normal, I suppose because the display is smaller and there's less processing power.

[Kiriakos-GR]

Update on the Fluke 85-3:
Fluke received it, put a battery in it, let it run over a weekend, and decided it was OK. Didn't even test the auto power-off function, not until I called them back on it and straightened them out.

I know that you are stressed , but some times , some things its our fault too !!

When an device goes for service , we should write and detailed report with any issues that we have,
so to inform properly the other side , of what or where to look at, or test.

I do that when I RMA from computer parts or even multimeter s .

 
 

[alm]

I know that you are stressed , but some times , some things its our fault too !!

When an device goes for service , we should write and detailed report with any issues that we have,
so to inform properly the other side , of what or where to look at, or test.

I do that when I RMA from computer parts or even multimeter s .

I agree. I've seen this issue from the other side, and it's pretty hopeless when you don't get sufficient information to reproduce the problem (not saying mzacharias did that, since I don't know the facts). You either call the customer, or do some basic tests and return it as 'unable to reproduce problem'. What else are you supposed to do if there are no obvious issues and the customer didn't tell you the specific steps and circumstances?

[mzacharias]

I know that you are stressed , but some times , some things its our fault too !!

When an device goes for service , we should write and detailed report with any issues that we have,
so to inform properly the other side , of what or where to look at, or test.

I do that when I RMA from computer parts or even multimeter s .

I agree. I've seen this issue from the other side, and it's pretty hopeless when you don't get sufficient information to reproduce the problem (not saying mzacharias did that, since I don't know the facts). You either call the customer, or do some basic tests and return it as 'unable to reproduce problem'. What else are you supposed to do if there are no obvious issues and the customer didn't tell you the specific steps and circumstances?

I believe I was clear enough - the information I gave Fluke was on a par with the original information I posted here. Excessive current consumption in auto power-off mode, over 700uA with display OFF, etc.
They apparently misread my description to read mA not uA. However if you think about it even briefly, this meter couldn't even run if it were pulling 700mA, and even if it did, it would only go a few minutes, and get rather HOT. They just weren't paying attention is my feeling.
I wonder if they put the new hires and kids on the multimeters, and use their best technicians for the higher-end stuff?

[mzacharias]

Regarding the Fluke 85 Series III:

Received back from factory service; no change. Not really that surprised - it seems likely there never was a later microprocessor version which (I believe) would have been necessary to fix the issue of excessive current drain in "sleep mode".

I have posted a video showing the problem and Fluke's response at:



Anyone with a 80 series III (83 or 87 series 3) I would be very interested if you could repeat the test on your meter and see if those models act the same. I suspect they do.

Thanks to all who took the time to reply.

Mark Z.

[Excavatoree]

For my Fluke 87-3 I have here at work:

I measured 890 ua in "on" mode, which strangely drifted to 972 as the meter was left on. (No back-light)

In standby mode, I measured 541uA, which drifted to 579ua in a few minutes. (strange, as I type this, it keeps going up. Ill edit my post if it ever stops - it keeps drifting)

I have no reason to suspect my Fluke 25 (with microampere range) is drifting, but I'll check again at home with some other meters.


 EDIT:

I'm not sure what the peak was, as I was unable to watch it 100 percent of the time.  I believe it got to 650 ua or so, then began to lower.  It oscillated from 520 to 600 microamperes, and has finally settled at about 524 ua. 

[mzacharias]

Thank you very much for checking. It appears that, as I suspected, the III series in general suffers from this "problem".

Seems that it should have been caught and corrected in the design / prototyping phase, but I guess there's nothing to be done at this late date...

Thanks again to any and all for their thoughts and replies on this issue, and of course if anyone else has comments, I'm still very interested in hearing them.

Mark Z.

[saturation]

I don't have an 87-3, but I did have a problem with drain in an 85I.  I cleaned the rotary contacts and all's well, its over 20 years old.

The sleep modes and other default modes can be turned off/on by certain key presses while you turn the meter on.  Have you tried toggling it off/on and see if that does anything?  Can't hurt.

[mzacharias]

I don't have an 87-3, but I did have a problem with drain in an 85I.  I cleaned the rotary contacts and all's well, its over 20 years old.

The sleep modes and other default modes can be turned off/on by certain key presses while you turn the meter on.  Have you tried toggling it off/on and see if that does anything?  Can't hurt.

I'm not sure what would be the point...

I can cancel the auto-power-off by pressing the blue button while turning on, but then of course it would not power off at all until turned off manually.
Likewise, if I press any button while in auto power-off mode, normal operation is restored, and current drain goes back to (in my case) 820uA.

So far as cleaning the switch is concerned, the issue has existed since new. I had chosen not to open the main case unless I might need to in order to change a fuse, but that had never happened, and now the unit is just back from Fluke with a fresh cal, so I have even less incentive to open it until I really need to.

Mark Z.

[saturation]

Yes, understood.  If the 85-3 software has a bug or oversight in it and not all the subsystems are actually turned off when it auto-offs, maybe whatever routine needs to be turned off can be invoked if you try switching the auto off mode off.  After its set once, maybe it will work as designed thereafter.  You can't really know until you try it, and given you can either accept the status quo or try it, its now up to you to find out.

I don't have an 87-3, but I did have a problem with drain in an 85I.  I cleaned the rotary contacts and all's well, its over 20 years old.

The sleep modes and other default modes can be turned off/on by certain key presses while you turn the meter on.  Have you tried toggling it off/on and see if that does anything?  Can't hurt.

I'm not sure what would be the point...

I can cancel the auto-power-off by pressing the blue button while turning on, but then of course it would not power off at all until turned off manually.
Likewise, if I press any button while in auto power-off mode, normal operation is restored, and current drain goes back to (in my case) 820uA.

So far as cleaning the switch is concerned, the issue has existed since new. I had chosen not to open the main case unless I might need to in order to change a fuse, but that had never happened, and now the unit is just back from Fluke with a fresh cal, so I have even less incentive to open it until I really need to.

Mark Z.

[mzacharias]

OK, when I get a chance I will perform the test again, and cancel the sleep mode by pressing a button, then let it sleep again after another 30 minutes. This is your suggestion, yes?

[saturation]

Yes, but also first turn off the sleep mode completely using the start up rotary switch procedure.  Then turn it on again.  Then see if the mA consumption is still high when it goes to sleep automatically.  I don't think there is anything more you can do as there is no system reset on the 87 series.

OK, when I get a chance I will perform the test again, and cancel the sleep mode by pressing a button, then let it sleep again after another 30 minutes. This is your suggestion, yes?

[mzacharias]

Yes, but also first turn off the sleep mode completely using the start up rotary switch procedure.  Then turn it on again.  Then see if the mA consumption is still high when it goes to sleep automatically.  I don't think there is anything more you can do as there is no system reset on the 87 series.

OK, when I get a chance I will perform the test again, and cancel the sleep mode by pressing a button, then let it sleep again after another 30 minutes. This is your suggestion, yes?

I don't think I can re-enable the auto power-off without just rotating the function switch to the OFF position and then selecting an operating mode, turning it on again manually.

Mark Z.

[Kiriakos-GR]

Well, if it is an software bug , an firmware update ( If there is one ) it will save it.
If not ...  get a better model .

What matters are  , if you the user,  can be truly productive with it ??  
If not ... sell it on ebay to some one who is an beginner ,  and you, get an more advanced one.

[mzacharias]

Well, if it is an software bug , an firmware update ( If there is one ) it will save it.
If not ...  get a better model .

What matters are  , if you the user,  can be truly productive with it ??  
If not ... sell it on ebay to some one who is an beginner ,  and you, get an more advanced one.

Well, let's see - I have an 85-3, an 87-5, a 77BN, a 27FM, an 8800A/AF, an 8840A...

Mark Z.

[mzacharias]

FLASH!!! FLUKE SERVICE HAS CONTACTED ME BACK AND THEY WANT ANOTHER CRACK AT FIXING THIS MULTIMETER!!!

AND...IF THEY CAN'T FIX? IT, THEY WILL GIVE ME A NEW 87 SERIES V !!!

THANKS TO ANDRE BLACK AT FLUKE!

They saw the Youtube video, and they are having meetings about this. Newer, younger techs didn't have their work 100% QA'd, phone support guy shouldn't have blown me off, etc.

Restores ones' faith, eh?