Voltcraft 6010 DMM (NOS from 1984) unboxing and teardown [picture heavy] - Page 1
Forum section: electronics / testgear

author: frozenfrogz
author_rank: Frequent Contributor
timestamp: April 05, 2017, 04:57:37 pm
content: Today my Voltcraft 6010 arrived!It has been sitting in some warehouse for 30+ years and finally will serve its intended purpose.This will be an unboxing and teardown with lots of images that I have upped to animgur album(in case you want pics without the talking).Edit:This meter was introduced in 1982 and was a real game-changer here in Germany, since it incorporated all state-of-the-art technology and features, but was 60% cheaper than the competitors (we are mainly talking Fluke 8020 here I guess). Keep in mind, digital multimeters just appeared on the market for the first time back then.There is a German article from the30st anniversary of this DMM./EditSo there it is, lying in its styrofoam bed, sleeping for the past 30 years...Included in the package is the meter, two test-leads with threading (roughly one meter and 20 centimeters, or about four feet in length), two screw-on alligator clips, a nine volt battery, certificate of guarantee and a manual.In case you want to take a look at the manual, I took photos and merged them into a .pdf that you can get here:https://document.li/oK4g- sorry, I was a bit lazy and did not do proper scans.Awesome Korean battery still going strong after sitting in a box for more than 30 years! Who needs batterisers if you can have that? *Alligator clips screwed on and disassembled.Front view of the 6010.Back view of the 6010.Made in Korea (obviously).WARNINGWARNINGCAUTIONWARNINGOK, I get it. I will be cautious. Arrow pointing towards battery eliminator jack, but this unit does not have one.CAUTIONThis Instrument contains no operator serviceable parts. Read operating instructions before use.I guess, we will see about thatBattery compartment.First look under the hood.I forgot to mention, that I really like the Star Wars AT-AT look and color scheme. And as a first nice feature (from a product designers view) we encounter brass threadings molded into the case! I was missing these on the Fluke 8020B I got last week.Also another WARNING + CAUTION, because: Why not?Side-note: There is a spare fuse tucked in the back of the case, wrapped in foam.The bottom part of the case incorporates a separate strip of molded plastic that sits under the switches.Back view, opened (sorry about the disastrous lighting).Some shielding, close-up of the threaded inserts and battery connector.Label on the shielding, let’s further disassemble and reveal the internals.With the shield removed and terminals disassembled, we can remove the internals form the upper casing.Product designers side note: Nice screw-in terminals for the win!Front view of the PCB - not much to see here, apart from the injection molded clear plastic cover of the LCD maybe.Teledyne TSC7106CPL (made in 1984?) - 3 and 1/2 digits A/D convertor, DIP-40 package for driving the LCD.SGS Thompson HCF 4030Bquad exclusive-or gate (made in 1982?)Partly convenient way of an on-the-fly strain relief.Some more close-ups of the input side.The white resistor networks read:Sunics 410A - HC-DMM-V (big one in front)Sunics 409A - HC-DMM-SNow, that we have seen the internals, let’s go figure if it actually works. Remember that awesome battery from the beginning?But it said 9.23V! What is going on?*In case you don't know what is happening here, go watch Daves batteriser video again.This cell is dead as door-nail - not too surprising after 30 years of self-discharging, even though alkaline 9V blocks can be quite impressive in this regard.Dropping in a fresh China made battery and...It’s working!Side-by-side voltage measuring with the old Fluke 8020B.Side-by-side measurement of a resistor clamped to the alligator clips with 8020B and UT139CSo there you have it, the vintage Voltcraft 6010 new old stock that no one wanted to buy for 140 Deutsche Mark and 93 Pfennig (51.04USD back in 1984).The price translates to roughly 132 Euro or 124 USD when comparing purchasing power now and then, taken from some calculator on the web.I purchased the old Voltcraft, because my father owns one from since I was born and still uses it regularly today. There is some sentimental value to it and I really like the look and feel. I can see why most DMMs on the market feature a turning knob selector, because these are way cheaper to manufacture and auto-ranging is OK, but nothing compares to being able to simply select the range you need by one press of a button compared to switching through various modes on a dial.The manual states 1000V DC or AC peak voltage non-switched, 750V AC peak voltage switched, but I probably would want to test it...Also from the manual:"Overload protection is guaranteed in all areas (except 20A range).To protect against excessive voltages, a gas-filled spark gap is used, which has proven itself better than devices with varistors. A pair of fast silicon diodes as well as a fuse ensure excellent protection in all current areas. Furthermore, the input of the alternating current transformer is protected against overvoltage."This is translated from the manual p.6To conclude, here is a better shot of the schematic I tried to clean up a little.Thank you for your patience in scrolling through this picture-heavy post (is there a way to resize the images, or some other convenient way to make it all a bit more readable?), hope you could enjoy it at least a littleFeel free to ask and comment!All the best,Frederik

author: frozenfrogz
author_rank: Frequent Contributor
timestamp: April 05, 2017, 07:30:51 pm
content: Short follow-up, because I forgot to talk about the test leads that came with the device.The test leads can be fully disassembled, so in case of a broken wire you can fully repair it *yay*There is some serious amount of copper in them, I measured a little over 1.6mm in diameter aka 14 AWG!The insulation is rubbery to the touch and has a nice matte finish. Compared to my Fluke TL71(?) they are very stiff, but that is to be expected I guess - given the wire gauge. Insulating plastic parts may be PVC or ABS, but that is just a wild guess. Casing of the meter is also some basic polymer - no glass reinforcement or anything fancy. The flip-up stand in the back serves its purpose, but it is a little flimsy, especially compared to the very sturdy one on the 8020B.Ascapt bullshotpointed out in the "what did you buy today" thread, the meter was produced by Hung Chang in South Korea. Some website stated, that the 6010 was originally designed by CTC (Conrad Technology Center) and their first big invention, going to be sold under the Conrad Electronics label Voltcraft and a huge success on the German market. But since there is the Hung Chang 6010 or HC601 (absolutely identical) and the HC markings are all over the PCB of the meter, I doubt that it was really a CTC invention. But who knows... Conrad Electronic by the way is similar to Radio Shack, but here in Germany.

author: GeorgeOfTheJungle
author_rank: Super Contributor
timestamp: April 05, 2017, 07:38:38 pm
content: Beautiful! And the Intersil... I remember that! There was another to drive led displays. But IIRC it dates back to the 70's not the 80's... (?)

author: frozenfrogz
author_rank: Frequent Contributor
timestamp: April 05, 2017, 07:55:27 pm
content: As far as I have read, Fluke originally invented the 429100 which was produced by Intersil. Intersil then basically counterfeited Flukes chip and sold it as their own product, the ICL7106. Where and when Teledyne started manufacturing the TSC7106, I don’t know. But both the latter seem to be rip-offs of the original Fluke design.P.S.: If you like to investigate a little further, here is the thread onthe history of the Fluke 8020that I just found (again).Edit: Oops, wrong tag on url :/

author: retiredcaps
author_rank: Super Contributor
timestamp: April 05, 2017, 08:12:41 pm
content: History of Fluke and ICL 7106 explained by one of the original Fluke 8060A team ...https://www.eevblog.com/forum/testgear/old-fluke-multimeters/

author: Vgkid
author_rank: Super Contributor
timestamp: April 05, 2017, 11:07:41 pm
content: That is really cool. Thanks for showing it to us.

author: cdev
author_rank: Super Contributor
timestamp: April 06, 2017, 02:26:43 am
content: Thats a very nice solid meter.Can you easily change the ranges with the meter in your left hand and a probe in your right?

author: frozenfrogz
author_rank: Frequent Contributor
timestamp: April 06, 2017, 05:20:09 am
content: Quote from: cdev on April 06, 2017, 02:26:43 amYes, that is absolutely no problem at all. The switches are easily operated with the thumb, since they are a nice usable size and feature a tapered / sloped top, just like the Fluke 8020s. Left hand, right hand, very convenient.

author: capt bullshot
author_rank: Super Contributor
timestamp: April 06, 2017, 06:20:04 am
content: Quote from: GeorgeOfTheJungle on April 05, 2017, 07:38:38 pmYes, thats been the ICL7107. My very first digital multimeter was a kit (sold by Oppermann, Voelkner, ?, can't remember) using a LED display driven by this chip. Next multimeter was the said Voltcraft 6010 - still wonder how I made my parents pay for all that stuff back in these days ...BTW frozenfrogz: great pictures, they make me feel nostalgic. Recognized and remembered the guts at first sight.

author: frozenfrogz
author_rank: Frequent Contributor
timestamp: August 29, 2017, 01:28:13 pm
content: As it happens to be, I found a couple of meters in the local small adds that were delivered today. Sadly they were not both Voltcraft 6010 (as advertised), but one Hung Chang HC601 and one Voltcraft 6010 (older model with only 10A max. range).Both power on, but have not yet been tested thoroughly. I already did some cleaning of the 6010, there was a loose screwpost for the shielding that I soldered back in place, the plastic insert behind the buttons is missing, other than that I need to do some more inspection.The HC601 is really messy. The case needs thorough cleaning and the PCB is flooded with flux residue. One thing I noticed is that the HC601 does not have the precision resistor networks that are featured in both 6010s.In the next days I will work on these units and take some pictures for comparison with the meter in the OP. That way y’all can take a look at the history/evolution of the 6010

author: cdev
author_rank: Super Contributor
timestamp: September 21, 2017, 04:13:08 am
content: As Edsel Ford Fong used to say. "Not too shabby"

author: Bill Fenton
author_rank: Newbie
timestamp: October 26, 2018, 09:32:43 pm
content: Hello Got one of these in Mid 1980s it was my first digital multi meter ( the Hung Chang Version cost about £35) it was so accurate for the Money and of quality construction. When I got my first job in industry I remember checking it by comparing it to a Philips multi meter pm 2517x which was calibrated to national standards, was only a couple of digits out on all scales. I also got a Hung Chang HM102BZ analogue meter from same supplier via Television magazine quality on these was poor. think cost was about £16. The 6010 died a few years back still have the HM102 mainly for the Buzzer the meter is not reliable. Not a Patch on my AVO EM272 still going strong since 1978. Now Have a couple of maxcom DVMs from the mid 90s cheap as chips and accurate Plastic deteriorating, geting bit brittle on one of them

author: threephase
author_rank: Regular Contributor
timestamp: October 27, 2018, 10:40:50 am
content: Nice review, certainly some good quality manufacturing options utilised, that have sadly been forgotten on a lot of today's instruments.Thanks for taking the time to post.Kind regards.

author: andi112
author_rank: Newbie
timestamp: March 28, 2019, 06:24:02 pm
content: Nice report. I bought this DMM in the beginning of the 80's.The layout is a little bit different of yours.As you can see the display isn't working poperly:Does anyone knows what could be the reason?

author: frozenfrogz
author_rank: Frequent Contributor
timestamp: March 28, 2019, 07:13:15 pm
content: Looks like a bad zebra strip connection.You need to disassemble the display frame and then clean both the PCB contact points and the rubber zebra strips with isopropyl alcohol.

author: andi112
author_rank: Newbie
timestamp: March 29, 2019, 10:01:38 pm
content: Thank you for the answer.I'm writing from Germany. So what is a zebra strip connection?The promt translator tells me: Zebrastreifenverbindung. I never heard it before.How did you managed to remove the display? On my board it is soldered (40pins!)

author: frozenfrogz
author_rank: Frequent Contributor
timestamp: March 29, 2019, 10:57:29 pm
content: Das sind dieLeitgummisdie die Anzeige mit der Platine verbinden.

author: andi112
author_rank: Newbie
timestamp: March 30, 2019, 12:02:33 pm
content: Schön, dass es auch in Deutsch geht!Die Frage bleibt, bekommt man das Display aus der schwarzen Halterung (welches wohl die Leitgummis sind?) heraus? Wenn ja, wie. Ich will keine Gewalt anwenden und dabei eventuell etwas beschädigen.Oder muss man tatsächlich alle 40 Pins entlöten?Bei Deinen Photos sieht man ja auch das Display und dann im nächsten Photo ist es weg. Man sieht aber auch die Verbindungsdrähte nicht mehr, geschweige denn die Lötpunkte, wo sie hineingehören.Weiss man, welche Bezeichnung das Display hat. In der Stückliste, die mir vorliegt, kann ich sie nicht finden.

author: frozenfrogz
author_rank: Frequent Contributor
timestamp: March 30, 2019, 01:12:52 pm
content: Wrote you a PN. Usually other languages than english are not really accepted here, so please let's discuss this in private.

author: GeorgeOfTheJungle
author_rank: Super Contributor
timestamp: March 30, 2019, 02:12:09 pm
content: Ach du lieber Gott!

author: andi112
author_rank: Newbie
timestamp: March 30, 2019, 02:44:13 pm
content: I forgot a picture of the display. Here is it. The quality of the handycam is not so good.

author: GeorgeOfTheJungle
author_rank: Super Contributor
timestamp: March 30, 2019, 03:00:21 pm
content: There's no zebra strip there...In the kit that Intersil sold in the 70's, the one with the 7106, the LCD was a DIL package, there was no zebra strip. The LCD was like this one:But this isn't a picture of the original Intersil 7106 kit.

author: frozenfrogz
author_rank: Frequent Contributor
timestamp: March 30, 2019, 06:43:12 pm
content: Well, that is interesting. I took another look at all of the 6010s I own (6010 10A version, 6010 20A version, Hung Chang 601 2A version) and all of them feature zebra strips connectors on the display.Bad segments are usually a sign of bad contacts / missing signal line to that segment. I would start by checking the board for possible corrosion and obvious defects in the area where the pins join the glass assembly.

author: andi112
author_rank: Newbie
timestamp: March 31, 2019, 09:13:28 pm
content: This looks a little bit like mine.See the attached picture.Do you think I can try to clean the contacts at the display with a Q-Tip and some alcohol?Btw I couldn't see any oxidation at the contacts.

author: andi112
author_rank: Newbie
timestamp: April 02, 2019, 03:14:32 pm
content: OK you can say: Trial and Error! But this isn't very useful if afterwards nothing is working anymore: Anyone here who has experience with cleaning the contacts of an LCD?

author: Idbid
author_rank: Newbie
timestamp: June 03, 2019, 10:49:37 am
content: I got hold of a similar meter a couple of weeks ago, it's a University (Yu Fong) YF-1100. Same side push button arrangement, also uses the Intersil 7106 chip. I think it may date from 1985. The 7106 chip wasn't working properly so I put another one in it, that seemed to do the trick. I can upload some photos either here or on a new thread if anyone wants, it might be interesting to someone. I couldn't find much information on the meter by Googling, except for a couple of similar ones for sale and some old magasine ads for it.This thread & posts encouraged me to have a go at fixing it, thank you!

author: andi112
author_rank: Newbie
timestamp: June 04, 2019, 01:01:10 pm
content: "The 7106 chip wasn't working properly"How did you realized this? Which error it showed?

author: Idbid
author_rank: Newbie
timestamp: June 04, 2019, 03:57:17 pm
content: Hi,It was a bit random. it would often say -1666 or just some other random numbers every few seconds. I read somewhere (I think on EEVBlog) that the 7106 shows 1666 or something continuously if the oscillator circuit is faulty. The analogue input voltage to the chip seemed stable and reasonable depending on the range and voltage applied at the meter input. The 7106 is in a pluggable socket so I decided to try swapping it, cost about $16 delivered. That fixed it. The display always worked OK though, so not really the same fault as you seem to have, but it might still be worth swapping the 7106 if you don't find anything else amiss. That's just a suggestion, I'm not an expert at all.I can put some pictures of the PCB up, either here or link it to a similar new post for info on my particular meter. It uses a plastic velum with conductive "zebra" stripes between the 7106 and the LCD, yours seems to be different in design there. The YF-1100 is all built up on the same top PCB side as yours though, the Voltcraft 6010 has components on the bottom side which is interesting.

author: Darn Tootin
author_rank: Newbie
timestamp: August 13, 2021, 05:33:53 pm
content: In case anyone is interested in aPDF digital version of the manual for the Hung Chang 601version of this multimeter,I have reconstructed it from a very old and battered paper version. This one is in color, so that's an added bonus. The layout is print ready, so if printed double-sided and folded mid-vertical, it presents itself correctly.So this is for posterity. I didn't know where else to post it and maybe someone, looking for the manual, will benefit." alt="" class="bbc_img" />Cheers!

author: Wollvieh
author_rank: Contributor
timestamp: August 03, 2024, 04:32:46 pm
content: I found a 6010 with 20A range in very used condition but still working.There are no manuals out in the wild, but it looks like the Huang Chang has an identical parts list and schematics as the Voltcraft 6010. So the Voltcraft should have the same specifications of 0,5% in DCV and 1% in DCA and ACV.I could drop it in the car instead of the bin. But for everyday usability I'm missing at least a continuity beeper.