EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: leppie on December 10, 2014, 08:04:34 am
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Hi
I picked up a Fluke 867B quite cheaply recently. Everything is working well, and the meter is still spot on (within a single count of my chinese voltage reference :-+).
The only probably I have is with the LCD (and what to call this issue, Google leads one down a very deep rabbit hole here).
I found some pics online showing the issue, and perhaps this is how all of them work? Note the dark areas.
(https://www.eevblog.com/forum/testgear/fluke-867b-lcd-issue/?action=dlattach;attach=123728;image)
The best description I can think of is "fading lines". What causes this? Could it be a flaky bypass cap?
There is a proper service manual and schematics for the meter online.
Any ideas?
Thanks
leppie
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I had the same issue when I bought a new one some time ago. They couldn’t fix the problem so they removed it. I sold mine.
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I have seen something similar on monochrome LCD displays where a soldered ribbon cable had failed. Re-heating the cable with a soldering iron or hot air was enough to reflow it and fix the problem.
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I had one with this problem. Only had it a few months after buying it on eBay. Another problem came up where it would not enter set-up mode. Can't say for sure the problems were related. All the functions worked but you couldn't change defaults etc. Tried replacing all the internal electrolytics - no good. Sold it "as-is" on eBay. Probably could have sent it to Fluke for an out-of-warranty repair, but the thing was 15-year old technology, and I figured that if I wanted a "scope-meter" then that is what I should have bought, anyway - the graphical display is pretty limiting in that regard.
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Thanks for the replies. So it seems this is a common 'feature'...
I picked it up pretty cheap, and just like it for the accuracy (not many handheld scopes of today can better it).
The scope part is toyish and the trigger modes are completely useless ;p
I will probe around the LCD power supply caps (dont really feel like removing it for testing ;p).
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Does anyone know what this effect is called?
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I'm not sure that this is really a "problem". I've had a 867b that I use almost daily since they first came to market and it's always looked like this. However it's never bothered me becasue when viewed from a few feet away it's not noticeable at all. Also, it has not gotten worse over the years. You're right that the o'scope feature is toyish but I love the waveform Combo display and just about every other thing that this meter does. The calibration is spot on vs my Fluke 8846A and has never needed to be adjusted. The only service it's needed is to replace the rechargeable battery pack -- which you can find, cheaply, on Amazon.
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I'm not sure that this is really a "problem". I've had a 867b that I use almost daily since they first came to market and it's always looked like this. However it's never bothered me becasue when viewed from a few feet away it's not noticeable at all. Also, it has not gotten worse over the years. You're right that the o'scope feature is toyish but I love the waveform Combo display and just about every other thing that this meter does. The calibration is spot on vs my Fluke 8846A and has never needed to be adjusted. The only service it's needed is to replace the rechargeable battery pack -- which you can find, cheaply, on Amazon.
Thanks, I'll just leave it be, and get used to it.
I also got a new battery pack from eBay, original completely dead.
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Though this topic is old, but related to my current problem. My 867B lcd when adjusted to a minimum brightness display a blotch at the center screen. First i thought some liquid enters the LCD but when i disassemble it, don't see any watermarks inside, though can be compensated by adjusting LCD contrast. Im just worried it may soon fade
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I had the same issue when I bought a new one some time ago. They couldn’t fix the problem so they removed it. I sold mine.
Do you know the reason for the DC offset in graph? I just have bought one, and it has the same problem.
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It seems a "bug" in firmaware, switching from text to graph page. May be isa problem due different response speed in 867 and 867b. It seems thant isn´t a bad o defective LCD. The efect is only visible when there is a moving graphic section in LCD.
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Someone with new firmware for Fluke 867, please :-/O :-//
Have FW 1.1 and the rotary knob for function selection is bitching around. I know it's that stupid voltage divider in the back, because if I pull the input of ADC with current from Keithley 2010 diode tester, that stupid meter sometimes jumps into the right measurement range.
Schematic is page 100 here:
https://dam-assets.fluke.com/s3fs-public/863_867_smeng0000.pdf
Voltage divider makes like 10 different voltages that go to directly into 10bit ADC of Renesas H8/510 microcontroller.
My hopes are that the guys at Fluke made wider ADC voltage window for each range in newer firmware versions.
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Plenty of used LCD`s on Ebay for the Fluke 867B...
Also used meters for insane prices.. 995 Eur.
https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2047675.m570.l1313&_nkw=Fluke+867B+&_sacat=0 (https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2047675.m570.l1313&_nkw=Fluke+867B+&_sacat=0)
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Same problem here.
Found this thread to late. I bought a lcd on Ebay and replaced it. Unfortunately the problem isn't fixed.
Either the issue is not on the lcdboard, or i bought a evenly broken one :palm:
For reference i run on fw1.4
Maybe as desperate attempt i will change the U13 > SED1335FOB chip if the sun and moon align just right.
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Please, let us know if you have any progress
Thanks
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I have discover a bad connection between carbon coatting and cooper traces in mine.
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From a internet forum:
"I had similar problem some time ago with SED1335 and 160x160 display. There
were also some lines moving around. The problem was with refreshing the
LCD(writing data to its RAM). It's not god to write to RAM at the same time
the SED is reading it. I think there is some signal LP(latch pulse), which
tells you, when the SED is not accessing RAM and that is when you should
access the display memory data. I think this is described in "Display Scan
Timing" chapter of the datasheet.
I'm not sure that is the problem in your case though.
Best regards, Tomaz."
https://www.electronicspoint.com/forums/threads/sed1335-flickering.22335/ (https://www.electronicspoint.com/forums/threads/sed1335-flickering.22335/)