Fluke 8060A replacement LCD Display with PCB and LEDs

[paraboliclabs]

I created this KiCAD project almost 2 years ago, and worked on it intermittently for a few days out of the past two years. It's a PCB version of Dmitri's wonderful 8060A LED display modification. I never did get this manufactured, because I figured I messed up something somewhere and I was too scared at the time to get one made and try it out on one of my display-less 8060As. I originally thought I read someone (ogdento?) had replacement LCDs made, but could never find information on where/who to bug about them, so I decided to make this KiCAD project.

A short while ago, Dave uploaded a video about the prototype Fluke 87-VI and I commented about 8060A. Dave talked about the forum and the AmpHour episode with DrTaylor in his comment, and I totally forgot about this place! Shame on me. Anyway, I thought someone here would love to have a starting point. So I've uploaded it to the internet and am posting it here for anyone to finish it/look it over.

I'm willing to get some PCBs made and do all the R&D for physical spacing constraints + create a LED shaper/blocker 3D print and release it all for free. Though I would like people who are far more knowledgeable than I am to look over the design, raise some issues/complaints/ideas.

I am hoping the whole thing could exist as a sandwich of the PCB, 3D printed LED shaper/blocker, and a thin piece of Lexan. If memory serves me correctly, the original 8060A display sandwich should be around 4.05mm - 4.10mm thick. The standardish PCB thickness is around 1.6mm + a 1mm thick clear Lexan sheet, leaving around 2mm of 3D print space, so it could theoretically work.

It should be noted, the project used a trace smoothing plugin, and I'm not entirely sure what it was. Though the repository has backups of the project before smoothing was applied.

Edit: I just submitted a precursory order to PCBWAY and only had to change via drill size from 0.1mm to 0.2mm. I updated the repository with the changes and it should be produced asap. I should get them on Monday or so. I have the same LEDs and resistors that Dmitri used. Can't wait to test them out!

Anyways, Hope you're all doing well. 

https://github.com/SaxonRah/Fluke-8060A-LED-LCD

[paraboliclabs]

I forgot to add the schematic.

Edit: I edited the "Fluke_LCD_d2mm.kicad_pcb" by adding teardrops, cleaned up some traces, fixed one last via, and smoothed the traces with arcs. This is probably the best version so far. I'll work on un-smoothing/trace-arcing and un-tear-dropping this PCB in a few. It's easier to have a raw PCB with non-smoothed tracks and no teardrops, then applying one after the other once it's routing has been finalized. It seems sacrilegious to not have teardrops and smooth arcs for this, lol.

I had two questions from a chat I shared this with, figured I'd mention this information here too.

1. The smoothing tracks is done with Round Tracks plugin. It can be found in the KiCAD official repository in the Plugin and Content Manager.

2. Yes, I would be interested in doing this again with other Fluke Multimeters as well. If anyone has suggestions on which ones to do next, let me know. I do have a an extra 8024b I can start off with. If someone wants a specific LCD done, I would need very good LCD pictures angled in such a way I can see all layers in the LCD and it's connections. This is harder than you might think. The newly added combined.jpg shows what I mean by this. (didn't realize you could add attachments in a post modification)

[paraboliclabs]

I got the boards in today, and I hand soldered one. There are a few things I'd like to change.

• LED pads should be slightly bigger to accept being soldered better. You can get away with the small pads as they stand by tinning one pad, then taking the LED in one hand heating up the tinned pad and sliding the LED into position with tweezers, then finally soldering the other side.
• The 1.00mm pitch header is probably too small for most people to hand solder enamel wire to reliably. I believe there is enough space for a standard 2.54mm pitch 22 pin header. This would also allow for easier testing as well before you'd wire it up to the multimeter.
• The half digit is the only "odd man out" in terms of cathode direction. Both half digit LEDS can be flipped in the PCB editor to align cathode direction with all the others. All horizontal LEDS have the cathode on the left, and all but the half digit have the cathode on top.
• Refine kicad project to include BOM for pcbway assembly options.
• Add test points for easy continuity checking.

Pretty sure that's all. I'd also like to build and write a testing jig and test program for a pico/pico2 to run through all the digits and functions. That'd be nice.

I got some other projects that need finishing first, but I'll give the multimeter a test in a day or two with the newly soldered LED PCB.

[paraboliclabs]

Interestingly, let's say you have a 1x23 pin header in a KiCAD schematic but choose a 1x22 pin header footprint. KiCAD does not automatically check for mismatched pin counts between the schematic symbol and the PCB footprint. This is a limitation in its current Electrical Rules Check / Design Rule Check systems. KiCAD assumes that the user manually selects the correct footprint for the schematic symbol, and it doesn't verify whether the number of pins on the footprint matches the number of pins on the symbol. This could be a nice thing to pull request, I'd imagine Electrical Rules Check would be the best place to do this for an Error, and additionally maybe a Warning for the Design Rule Check. I'll probably clone and pull request that sometime in the future. Shouldn't be that hard, it's just a comparison of pin and pad values.

Suffice to say, I missed a pin. I selected a 1x22 pin header footprint instead of a 1x23. It's not that bad of a mess up tbh. From the Hz cathode pad, you'll need to solder a wire from that side of the LED, and that wire is the missing pin 23. Thankfully it's not a total brick, well not a total brick so far. I've yet to actually solder it to the meter. Today I spent my time tracing and figuring out what pin I missed on the board. I guess I could have soldered it up instead of typing this message lol.

I am going to reroute the entire board and change everything I mentioned above and probably spin a few more boards. In addition I'll probably move the pin header from the top to the bottom to make the connection runs shorter and so that wire doesn't need to run from the top to the bottom of the display. I think I should shift the entire LED layout 0.5mm to the left also, so it's more centered in the plastic support piece.

I had thought about putting a surface mount female header on the Fluke LCD PCB where the tubular elastomeric connector sits and have the LED PCB have male pins on it and make it plug-in-able. However without redesigning a new LCD support piece, I'm not sure this could be assembled. I messed around with some perf board and headers, and you can make the LCD's angle with standard size 0.64mm pins angled in their holes, though I'm not sure on the female header with the height limitations. Not to mention with how the Fluke PCB slides into the plastic support, IDK how the female header would interfere. I was trying to make this without elastomeric connectors or plastic modifications and have it original as possible with minimal wires, but maybe I should keep that elastomeric tube and make the LED PCB just slide in like the LCD with no soldering required? Hmm... decisions, decisions. If I move the header down to the bottom, I can test that elastomeric tube connection too. I'll go solder it up now

[daisizhou]

Your replacement circuit board doesn't look perfect.Because it lacks a simulated progress bar indicator.

I have a suggestion,You can use 0805 or 0402 packaged LED lamp beads,It is also recommended not to use PCB circuit boards,Because you also need a light-blocking plastic baffle.

The best solution is to use an aluminum substrate，One side is an aluminum plate, the other side is circuit wiring, the middle is directly hollowed out to form a hollow digital tube hole, and there are also holes for symbols such as "HZ" and "V".
The light-emitting LED is soldered on the wiring side.When the LED is lit, the light passes through the aluminum substrate (opaque), and only the holes that meet the hole symbol are transparent.
I think this is perfect.

I put a similar solution, please see the picture

[paraboliclabs]

Your replacement circuit board doesn't look perfect.Because it lacks a simulated progress bar indicator.

I'm not sure what you mean by that.

I have a suggestion,You can use 0805 or 0402 packaged LED lamp beads,It is also recommended not to use PCB circuit boards,Because you also need a light-blocking plastic baffle.

The best solution is to use an aluminum substrate，One side is an aluminum plate, the other side is circuit wiring, the middle is directly hollowed out to form a hollow digital tube hole, and there are also holes for symbols such as "HZ" and "V".
The light-emitting LED is soldered on the wiring side.When the LED is lit, the light passes through the aluminum substrate (opaque), and only the holes that meet the hole symbol are transparent.
I think this is perfect.

I put a similar solution, please see the picture

I do like this approach, as it reduces the height by recessing the LED in the PCB, in addition to shaping the light with the PCB itself. Also the heat dissipation of an aluminum PCB is a good reason to go that way. One problem I have with changing the type of LED is that Dimitri did all the research and claims to match the current draw of the original multimeter LCD. I worry that changing the LED type would offset the draw by some non-negligible amount. I personally really love that his LED mod draws the same as the original LCD. I'm not sure how the LDC driver would handle different LEDs.

Luckily heat really isn't a problem here as the LEDs are just barely powered, the Fluke 8060a LCD driver doesn't deliver much current and what it does deliver barely passes the threshold for solid green 0805 LED illumination. I was mostly just following the previous work done by Dimitri http://mrmodemhead.com/blog/a-very-unique-fluke-8060a/ Since he already did all the hard work researching and testing the 8060a meter and it's LCD current draw. For what it's worth, I did leave the LED PCB connected to a power source delivering slightly more current than the meter provides overnight and couldn't feel any warmth from any of the LEDs in the morning.

I do like having a light-blocking plastic baffle, I can reduce and shape light bleed by creating walls for each character segment. But maybe I'm alone on that front.

I appreciate the suggestions, you've given me some interesting things to think about.

(It should be noted, I'm not an electrical engineer, I'm just a programmer by trade and enjoy electronics as a hobby. So If I'm wrong about something, it's because I really have no clue about electronics, I'm all self taught in this area. All of my PCB making experience is from making flex PCB for various cameras to siphon out image data to FPGAs. So really all I've ever done is make flexible pcbs that have tracks that connect chip footprints to pin headers. This LED PCB is the most complicated thing I've done in any PCB software. I've never even needed to use vias until now. lol.)

[daisizhou]

Your replacement circuit board doesn't look perfect.Because it lacks a simulated progress bar indicator.

I'm not sure what you mean by that.

Lack of simulated progress bar indicator and "BT" mark display

[paraboliclabs]

Your replacement circuit board doesn't look perfect.Because it lacks a simulated progress bar indicator.

I'm not sure what you mean by that.

Lack of simulated progress bar indicator and "BT" mark display

There is both a "Bar" LED and Low Battery LED in the original PCB and schematic. I did want to add 2 more LEDs to the bar circuit and have a small translucent resin piece for the Bar in the light blocking plastic, but I'm not sure the added LEDs would be bright enough and what adding LEDs might do to the rest of them. I should test that out with a bodge and see if it's possible. One LED might even be enough to light the whole translucent resin piece. I'll have to investigate that too. I do like having the design be original looking as possible, so long time users wouldn't have to relearn the display.

-

BTW Here is the current redesign with a silkscreen to measure out the cutout of the meter. The original PCB was way too spread out and the bezel cut off most of the display. Yes I'm an idiot. I didn't measure out the bezel originally, and when coming back to the project, I totally forgot about having the need to do that and assumed I measured it. 

[daisizhou]

I think it's best not to change the display position, because I want to pay tribute to the original designer^_^

Regarding the analog progress bar display, I think you can use 0603 and 0402 packaged LEDs, because they look very delicate and there will be no intermittent display. Of course, welding may be difficult.But in other words, for amateurs, welding will not be a problem.

These symbols and simulated progress bar displays have been added. As you said, the current will inevitably change, but I think the desired current value can be achieved by adjusting the resistance value.

In general, the perfect solution is to replace the original LCD monitor 100%.

I remember that the 34401 multimeter had an LED replacement solution, and I hope the 8060A also has a replacement solution

[paraboliclabs]

Here is how bad the cutoff with the original PCB I made was with measurements. At the very least, it all worked (with the bodge) lol. 

Here is that TempPrototype I previously posted, printed on paper and glued to an extra "failed to measure" PCB. I'm getting smarter, this obviously should have been done originally.

Using the tubular elastomeric connector that the original LCD used is possible. I'll just need to draw my own 1x23 footprint for the pads.

[paraboliclabs]

Small update with everything routed and test fitted. The elastomeric footprint on the paper looks a bit off, but it's the camera's perspective messing with the view. The traces all line up very well. It's exciting that no soldering will be required and the original plastic LCD cover can be used. It's basically a drop in replacement! Provided it works as expected. Probably will send this out to PCBWay in a few days. Going to mess around with BOM and assembly setup first. I decided against rounding and tear-dropping tracks, for now.

Dang, my lunch breaks are going to be boring now that this is almost done. Oh I'll update the github with this version also. Have a good day!

[blue_lateral]

For what it's worth, there are at least 2 different versions of the stock LCD brackets and the stackup of display, lens etc. that goes in them. There might be three.

Of the two I am semi-familiar with, one version has a separate polarizer and one doesn't. That makes the thickness of the stack slightly different, and it is unclear to me whether the parts can be mixed and/or to what extent. If you look at your picture below, you will see two beige alignment keys down at the bottom by the contacts. Those are slightly different on the other version of the bracket. At a minimum it prevents you putting the polarizer where it doesn't belong.



It follows then that the space the stack of lcd, lens, etc. rides in is also a different thickness and one might need to change update the bracket if you update the LCD? Or maybe leaving the polarizer out is enough, but somehow I don't see how that could be. I also wonder whether this affects necessary thickness of the zebra strip. There were 2 kinds of zebra strip, but I don't know if the change corresponds in time to the LCD/polarizer/bracket change. The early one kind of looks a pink tootsie roll and the later one has more or less a normal zebra strip look.

Additionally, near the end of the run the LCD changed again and the digits got bigger. That may imply a third setup? I have one unit that probably? has the big digits, but I've not taken it apart.

I had planned to document all this for the "Old Fluke Multimeters" thread, as I have some 8060As that are kind of stuck mid-rebuild right now. Life got in the way. I'll get to it eventually.....

[paraboliclabs]

For what it's worth, there are at least 2 different versions of the stock LCD brackets and the stackup of display, lens etc. that goes in them. There might be three.

Of the two I am semi-familiar with, one version has a separate polarizer and one doesn't. That makes the thickness of the stack slightly different, and it is unclear to me whether the parts can be mixed and/or to what extent. If you look at your picture below, you will see two beige alignment keys down at the bottom by the contacts. Those are slightly different on the other version of the bracket. At a minimum it prevents you putting the polarizer where it doesn't belong.

It follows then that the space the stack of lcd, lens, etc. rides in is also a different thickness and one might need to change update the bracket if you update the LCD? Or maybe leaving the polarizer out is enough, but somehow I don't see how that could be. I also wonder whether this affects necessary thickness of the zebra strip. There were 2 kinds of zebra strip, but I don't know if the change corresponds in time to the LCD/polarizer/bracket change. The early one kind of looks a pink tootsie roll and the later one has more or less a normal zebra strip look.

Additionally, near the end of the run the LCD changed again and the digits got bigger. That may imply a third setup? I have one unit that probably? has the big digits, but I've not taken it apart.

I had planned to document all this for the "Old Fluke Multimeters" thread, as I have some 8060As that are kind of stuck mid-rebuild right now. Life got in the way. I'll get to it eventually.....

That's really good and interesting information! I appreciate that. I have two 8060As and the one I've been designing everything on, indeed has the "pink tootsie roll" zebra strip. The pink tootsie roll version has a display sandwich thickness of 4.05mm - 4.10mm, it's alignment keys are 6.10mm wide and 9.90mm wide.

I just opened up the one I've never had problems with and it has a more normal rectangular zebra strip and has the same size LCD alignment keys/clips that are both 6.10mm wide. It's display sandwich thickness is between 4.08mm - 4.40mm, (measured from edge without polarizer, and measured in the middle of the LCD with polarizer). I put the PCB, paper printed, and plastic cover in and it fits with the elastomeric pads matching up. I also slid the older unmeasured LED PCB with plastic cover and it fits as well. If the elastomeric connection layout is the same, which I imagine they are, then the newest PCB should work on at least these two variants. So that's great news! I'll have to look at the LCD on the other one and verify the elastomeric connection layout is the same. I would assume they are.

Curiously I never noticed the backs are different too. The pink tootsie roll one, has embossed (raised) lettering and the regular zebra strip one has debossed (lowered) lettering. That one, the non-pink-tootsie-roll also has "Listed 950 Z" and "UL" circle at the bottom.

I have seen other 8060As that's missing the "Everett, Washington" text with a CE emboss next to the UL circle, I wonder if this is the third variant that you previously described. If it is, I can try and get one.

Thanks again.

[paraboliclabs]

Small update, I edited the LED footprints to make them easier to hand solder. Rerouted some traces to account for larger LED pads. Shifted the elastomeric footprint to align better. Fixed the KiCAD project. Added Thanks and Fluke silkscreens. Submitted new order to PCBWay. 

I couldn't ensure the LEDs used by PCBWay were the right ones, so I will forgo assembly at this time. The github has been updated with all changes and fixes applied.