Fluke 5100B - Part 1

Workshop Project #34 - Fluke 5100B
Now what did I get myself into now?! I was browsing e-bay and looking for some affordable - that is below 5 digit including delivery - solutions for reference voltages and currents; as in calibration refrences for my ever growing multimeter collection. So that they at least agree to a certain degree and are close enough to a real absolute value to comfortable switch between them during repairs.
Now the only affordable model I found was a Fluke 5100B calibrator. It can deliver AC and DC current and voltages in a rather broad range: from millivolt to 1100 volts and microamps to 2 amps. Both in DC and AC. There was a problem with the delivery though and I still think that the company behind e-bay global shipping service should compensate me for the additional cost in replacing the cheaper one of the two devices that they lost in transit... seriously: how does one loose a 40kg package?
This one - the second best offer I found - required some "close your eyes and click buy now" and my wallet feels considerably lighter now. Let's see what I got and how well it works... or not!
0:00 Intro / Overview
1:25 Opening Up the Case / Auction Overview
3:05 Overview of Inside / Summary / Modules: Digital, First Section
4:19 Modules: HV Transformer, Shielded ones
5:33 Power Regulator / Ranging Module
6:30 Front Panel Removal / Diagonal Bus / Transformer
7:29 Digital Bus PCBs / Rear Panel
8:45 Main Bus PCB
9:49 Case Panels / PSU Board
10:53 Front Panel Disassembly and Overview
11:42 Cleanup! Base Plate / Power Supply Interconnect
13:02 Mains Transformer Cleanup
14:08 Power Supply PCB Cleanup
15:58 Filter Cap Problem...
16:43 Mains Switch
18:45 Finalizing Power Supply PCB
19:30 Broken Trace! Fix and Overview
21:10 Filter Caps / First Components on Frame!
22:20 Main Bus PCB Mounting
23:45 First Power On...
24:38 ...Voltage Problem! / Frame Brackets / Digital Bus PCBs
26:57 Summary / Credits / Outtake
Music (in order)
My Train's A Comin' - Unicorn Heads
Nine Lives - Unicorn Heads
Wrong - Dan Henig
Town of 24 Bars - Unicorn Heads
Light Expanse - Unicorn Heads
(KZbin Audio Library)
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and now also here by using the "Super Thanks" feature!
Thanks to everybody who signed up already!

[@reps]

wow, nice one! I am working on one of these too

[@Runco990]

Marco, are you going to post a video on that? Been missing your dry humor....

[@georgem6651]

Hah! Can't wait to see who does it better 😁

[@atkelar]

It's a small world at times 😆 - it took some time to find the fault in mine; I'm sure I went through just about any part of it several times over, with only few exceptions.

[@lwilton]

I've had a 5100B for many years. The only instrument that lives on it's base on the floor rather than on the bench. Holds down part of the crustal layer in my area to prevent earthquakes.

[@matthiasjagdm3949]

4:39 not watch for long time and i am loving you describe your "assistant" as a different person

[@atkelar]

Practically, it's either that or "wear matching gloves" for the videos. But that would be... umm... clumsy and potentially dangerous if power tools or fire is invovled. So I chose to keep the lore of somebody doing the actual work for me, because paws need to be protected from harm and dirt! 😺

[@TeslaTales59]

Mr. Atkelar, you took on an enormous project! You may need to make this a 10 part series. Great work as usual sir.

[@RetroTinkerer]

Damn you are a fearless kitty indeed, that looks like some complicated stuff, hope you find the perfect reference to calibrate your reference!

[@atkelar]

Proper "by the letters" calibration would need quite a few standards. But I'm sure that a modern 7.5 digit DMM that is up to date and calibrated would do just fine. Problem is: finding one of these for rent, because I don't need something like that around normally...

[@janno288]

I am impressed how someone can not lose their sanity when working on something this complex and just starts replacing components without even powering it up first Hahaha! I respect your dedication, not just doing a restoration but also taking the time to use your character and recording all the voice lines! I wish you the best!

[@atkelar]

Thanks! I usually avoid power up until I have a clear insight into the device. Just so I can replace obviously faulty - and presumed faulty - components first, before they have a chance to take others with them. Especially with older devices that rely on no-longer-made parts.

[@Derpy1969]

Come for the restoration. Stay for the puppet.

[@PapasDino]

A true "magical mystery tour"! Can't wait for part 2!

[@lulrik1]

good video ! love the device as much as the musics you choose

[@Runco990]

Ohhh.... THIS will be FUN! I have a 5100 I'm restoring. There are loads of fun little problems with it! Stock up on extra boards if you can. You have the newer processor, so the empty slots in the back are normal. The original was a 3 board stack.

[@atkelar]

Ah! That explains the empty slots. I know there's been quite a few revisions, given the random differences in design and copyright date on my collection of PCBs... including some botches that seem to be part of a newer revision, as they add up with the schematics I have. The practical side is done, and once I find a decent modern meter to do the calibration proeprly, I can tell if there's any accuracy issues; at least "ballpark" works fine though. *knocks on wood*

[@Runco990]

@@atkelar An HP34401A meter will do you well. The fluke is really only accurate to 4 1/2 digits. BEWARE of the tantalums on the power rails!!! At least you don't have the "Red Devils". Most of mine were shorted. Your calibrator is much newer. Mine is a 5100, but it was new in box. Got it free because it never worked. Several people looked at it and gave up. The "it's totally dead" fault turned out to be a bad 555 timer IC which is the CLOCK for the bus. This IC is intuitively located in the bottom right hand corner of the regulator board. Where else would they put the bus clock? You'd THINK the CPU would clock the bus, but nooooooo!!!!!! It took me weeks to figure this out. After that, it booted. And.... then the fun began, as the tants shorted, etc. I have mine in a running state, DC is fine, AC still needs work. It's a challenge. More a toy, as like I said.... It's so old that it is only a 4.5 digit calibrator. My meters are 6.5. But it still has MANY uses. I have spare boards now for the whole unit. It can be a real headache, hope yours goes well.

[@atkelar]

I'm happy if all my meters are calibrated to 4 1/2 digits - I don't think I'll need more for anything but the calibrator itself 😇 - The 555 timer is labelled "RTC" in my schematics, I thought it would be some more of a "reference" for the CPU to use for timeouts and similar things? But yes, so far everything works and I don't see any shortet capacitor, but I got myself a set of replacement fuses for exactly that reason... Given the "oomph" of the transformer, I'd expect either a blown fuse or a blown capacitor if any were shorted. Neither is the case so far.

[@Runco990]

@@atkelar The "RTC" is certainly not a real time clock. It does provide the strobe for everything else. If that chip dies, and they DO, you'll have nothing. Not even an led lit. I threw that in for your FYI files. It's not a common problem, but very misleading if it happens. I swapped out the CPU initially, because the ancient original one was prone to failure. You are very lucky to have found a later and fully optioned out one. I am still hunting for those options for mine. But I'm in no rush. Looking forward to part 2! BTW, if you CAN, back up the Rom chips!

[@atkelar]

Well, it's listed as RTC; and since I probed it to run at about 60Hz I assumed it was just a reference for "seconds"; I didn't follow the signal any further... But I also can't find any references to that signal anywhere else. The front panel PCB has it, but it's dropping out on a pin that is labelled "spare, N/C" there, and it's running over the diagonal bus... When I open up the case again, I shall beep out where it goes. It might be connected to the reset circuitry on the controller, there's a sus line labelled "RT5" on there that is connected to the CPU reset via a line that is labelled "fline" (sounds like line frequency to me; and looking at the input with a zener diode, it seems that it's supposed to take direct sine wave input. Maybe other devices that use the controller pick up the line frequency from there?). That would explain the lack of movement when it's missing too. Figure 7-18 in my manual.

[@JoeMuc2008]

My respect to you Sir, I would have lost track of what goes where within minutes. What a majestic piece of kit. Hope you get it to a perfectly working state. Looking forward to the journey!

[@Pulverrostmannen]

Hey! I got one of these Unigor meters myself! Mine is the "Unigor 1P" Btw the Puppet master is at it again great work as always!

[@atkelar]

Unigor had quite a few meters back in the day. They were popular with schools, which is where I came into contact with the A43 one. I got it for nostalgia of "the first ever meter I used" back in 1991-ish. And thanks!

[@KeritechElectronics]

...and now let's try this once again just to see if it was not a Fluke! Lovely rebuild.

[@georgem6651]

Just made my Sunday watching this 🥹 Thabk you 😁

[@TheDefpom]

Welcome to the slippery slope of Voltnuttery, it’s a dark dark place 👍🤓

[@zyeborm]

He's already got a pretty cool accent, he's well on the path to the dark side 😂

[@msylvain59]

First time I see this design of "reversed" card edge connectors.

[@HainjeDAF]

@marcoreps are you watching this? I think you two could team up

[@jspencerg]

Thanks!

[@atkelar]

No, thank you! ❤️

[@andersvandegevel8355]

You don't need a capacitance meter to check capacitors; you can get usefully accurate results using a simple resistor and working out the RC time curve. The leakage is best measured with a sensitive ammeter once it's saturated and at the voltage you intend to operate it at. You can measure the ESR with an FG, a DMM, and a bit of Ohm's law cogitation

[@jspencerg]

Pulling pcbs: the hole in center-top of boards is there for a puller hook. You never hesitate for a complete disassembly! Fearless. Fluke issued change to reverse direction of fan. No filtering now. They realized there were cooling issues! Machine looks clean compared to mine. Perhaps the fault limited its use long ago? I'm looking forward to your tests. Thanks!

[@atkelar]

Hmmm... reverse direction compared to what? Mine came with the fan blowing out the back, which seemed odd, becuase it blows through the filter rather than sucking the air in. Is that the old or the new direction?

[@jspencerg]

@@atkelar Yours has been changed. The fan originally pulled through the filter. The filter now impedes flow and should not be used. I found the fan change document online.

[@feicodeboer]

Man, how on earth do you remember how to put back all those parts?

[@atkelar]

The videos and pictures help a lot! 😊

[@marcwolf60]

Photo's.. :)

[@YuriyKrivosheyev]

Great, thx! Then you’ll need a reference to calibrate a calibrator (as you mentioned already)… 😂

[@TinkerLynx]

Just found your channel, loved this video. As a small request, I just wish the music was at a lower volume. It's a fairly common issue for youtube and me (I have a bit of hearing damage) where I have to have the volume hi to understand the narration but find music distracting and louder then comfortable. Anyway, I've subscribed and I'm looking forward to part two, but for now I'll go watch some of your older videos.

[@atkelar]

Thanks for the kind words! I'm afraid it's a bit difficult to put the music to a significantly different level than it is now; it is quite a few dB lower than the voiceover and since everybdoy's listening devices are inherently different, it's next to impossible for the creators to predict how something will sound "on the other side"... I might be able to tone it down a tiny bit more, but on my end it's at elevator music level compared to the voice over.

[@TinkerLynx]

Thanks. I'll manage, using headphone vs speakers just about solves it for me anyway.

[@shawnhuk]

Ah, we see stagehand has a long grey beard! A clue!

[@atkelar]

The beard is still an experiment... not sure if/how long Stage Hand will keep that 😆

[@crispy_otter]

Purr-fect!

[@wall_k]

Huh, first time you can't make a lifesized cat modes out of the dust found inside

[@atkelar]

I have a theory on why this device was put away. That can line up with the relative cleanliness inside. I'll post that after part two though, need some pictures to go with it.

[@senilyDeluxe]

There's a chance these capacitors could outlast whatever you would have replaced them with.

[@FoxMccloud42]

And also on these type of equipment when you replace the caps, you need to recalibrate the hole unit, which can be costly.

[@atkelar]

Since it had some broken components, I have to do that anyhow ^^

[@atkelar]

I usually try to find "as close to original" ones as possible. In this case, the same lot of screw in capacitors from Sprague would have been a small fortune. I'm sure I could have found similar cheaper ones, but that would be a downgrade indeed.

[@ruawhitepaw]

@@FoxMccloud42 Calibrating the calibrator. Is it calibrators all the way down?

[@jspencerg]

@@FoxMccloud42 The need for recalibration depends on the specific function cap is used for.

[@HK_808]

I recently got a fluke 8500 im trying to get running again

[@atkelar]

Oh! That looks like a nice meter! I have some similar ones in my pipeline, but they first need to make it through the mail. I love these old devices; one can still find schematics for those.

[@HK_808]

​@atkelar luckily it uses mostly standard 4000 series cmos logic. According to the calibration sticker mine was from sperry-univac originally

[@mikehughesdesigns]

High Electronics. For Kids!!!

[@atkelar]

While I like to see my work as "kid friendly" - it is certainly made for at least young adults. I'd rather not have kids work on mains voltage devices 😆

[@leongyokeloong5083]

Is that a black cat?

[@atkelar]

Indeed. 😺

[@leongyokeloong5083]

@@atkelar very cute.