EEVblog 1665 - Keithley VFD REPAIR 2 - Electric Boogaloo

[@faust-cr3jk]

Dave actually fixed something. Unbelievable!

[@dav1dbone]

Rumour has it, if you break a tube in the southern hemisphere, the getter easily catches 40 billion oxygen atoms, Dave has been monitored by Guinness World records getting 89 billion, they reckon he was helped since more than half fell out because it was upside down

[@RandomUser2401]

yeah. not a lot of these. lots of talk for a recap though.

[@EEVblog]

@@RandomUser2401 You must be new here, welcome.

[@Schroefdoppie]

​@RandomUser2401 Dave? "waffling"? Surely not 😂😂😂

[@BobSacamano-dy3wg]

17:25 Nobody was more surprised than Dave.

[@mikesradiorepair]

Getter does not stop contaminates from getting in or out of a vacuum tube. It's not a sealant. It is flashed by inductive heating after the tube is sealed and when a gas molecule that escaped from being vacuumed out hits it it chemically combines and is absorbed into the getter.

[@jodiunger9425]

A getter does not stop gases from entering, it consumes gases that may come from the metals and whatever else inside, if the getter is not turned white, you still have a good vacuum, no if and or buts about it.

[@gorak9000]

I'm also sure it doesn't have "phosphor degradation" - if it did, the digits that are on all the time would be much less bright than a lot of the characters that are hardly ever used - the whole thing looks super uniform to me. I think that's just as bright as the VFD ever was

[@zaprodk]

@@gorak9000 Correct, but the emissive coating on the filament wires burn off after x amount of hours and there is nothing to do about that.

[@benespection]

Awesome Dave - happy you came back to this one :)

[@JFirn86Q]

Junk bin wins are precious, and must be thoroughly celebrated & paraded, as the missus needs to be reminded why she allows you to keep so much junk.

[@Cameron_D]

Love the repair videos :)

[@MikeB_UK]

So glad you had a go fixing the original display and great you managed. Totally agree that fitting the most readable, useable display is the way to go as this is a lab test tool you are going to use, not some piece in a historical museum.

[@StinnettsBodyshop]

LOVE THESE VIDEOS SO MUCH! I THINK THE LCD IS WAY BETTER!

[@mUbase]

ugh Tantalum tantrums . Excellent work Dave :)

[@Marzec309]

The first pcb I built had tantalum caps. Needless to say, i didn't know at that time they were marked backward from other caps. Talk about traps for young players. Boy.. did I learn in a hurry when i tried powering it. Firecrackers, those little buggers are!

[@Throckmorton.Scribblemonger]

Tantalum caps aren't marked backward from other caps that have the same shape, though.

[@Marzec309]

The only ones I'm aware of are not polarized, unlike tantalums.

[@simontay4851]

By marked backwards he means that the + pin is marked on tantalum caps. On electrolytic caps, the - pin is marked.

[@100-pc-notbot]

I love the look of VFDs

[@sloth0jr]

VFDs are so cool. Miss 'em.

[@guytech7310]

You can still buy them. Noritake on Mouser, Newark, etc

[@neongreenwool]

@@guytech7310 I use Noritake ones myself. There's a product at one of my jobs that had a bunch of failures with those displays, and were throwing them out. It turned out that improper installation in the product lead to the onboard fuse to blow. Being the renegade that I am, I bridged the connection for the fuse and had no issues whatsoever running them in my Arduino projects..

[@Chris558576]

Great video worth the watch.

[@IanScottJohnston]

Don’t forget you have those Sequre desoldering tweezers Dave, save you ripping pads of those SMD caps.

[@EEVblog]

Yeah, didn't have it set up ready though, I was lazy. I think the PCB doesn't use the best quality laminate glue.

[@uiopuiop3472]

we gonna need to see that weller wmrt in action tho!!! its very good and you must get it (top secret info- i am at trefort highschool until further notice ('gonna be banned soon')

[@guytech7310]

Hot air rework station repairs all SMT!

[@gregorymccoy6797]

Nice video. I love the VFD personally but the LCD does look good enough.

[@andymouse]

That's not quite right regarding a getter, It's not a seal. In a VFD display, the tungsten (barium) is vaporized after the seals are confirmed. It reacts with and traps residual gases by forming stable compounds, preserving the vacuum for proper tube operation. Basically anything left in there is absorbed. But when broken they go white. Don't scrap the VFD ! I think you should drive the anode a bit harder like you are doing on the backlight to brighten it up and keep the LCD as back up ! anyhow the whole thing is a good weeks worth of chicken dinners. People who shotgun caps also use Autorouters....nuff said.

[@EEVblog]

Not worth my time dicking around adjusting the anode voltage just so I can put the VFD back in and have it have an even shorter life. The LCD will last forever without any dicking around.

[@paulmcgrath2175]

​@@EEVblogunless it goes black like ones made in the 1980s.

[@paulmcgrath2175]

One could buy a new vfd, but they are very expensive to source unless you can score a surplus one. I might even have one in the bin but shipping to Australia is expensive unless it's needed.

[@guytech7310]

@@paulmcgrath2175 "buy a new vfd, but they are very expensive" Not really, NewHaven & Mouser sells the same model for about $42 New (M0216SD-162SDAR8). They are more expensive then LCDs, but not very expensive.

[@KeritechElectronics]

Nice come-a-gutsa on that cap indeed! So good to see it work again. I'd keep the VFD in, it's a thing of beauty, joy for ever.

[@CammyFi]

Love a good VFD

[@EEVblog]

Only if its bright...

[@ulfg1409]

@@EEVblog He specifically said "a GOOD vfd", it isn't good if it isn't bright. ;)

[@petersage5157]

But he didn't fondle the nipple!

[@foxotcw30]

Bookmarking this. I love VFDs, especially the 16-segment ones. No LCD display can compare in sheer timeless classiness.

[@EEVblog]

Unless it's dim, and then it kinda sucks.

[@ulrichfrank4270]

Timeless? The degradation timer is always running...

[@linmajon]

​@@ulrichfrank4270A friend have a Pioneer timer with VFD display running 24/7 since 1980 with zero service. Brightness is bot bad so far.

[@MaxPivovarov]

At the beginning of the last video, the first thing that came to my mind was: wouldn't it be easier to replace this with an LCD rather than buying an expensive fluorescent display? And you came to the same conclusion at the end. By the middle of this video, I thought, no way, why replace a perfectly working LCD with this dim, half-dead display? And I’m glad you decided to keep the LCD. All these steampunk fluorescent displays are fine for novelty projects, but not for tools where reliability and longevity matter.

[@peterferguson2344]

Nice one Dave, great job mate. 😁👍 Greetings from Ireland 👋😁☘

[@edgarcornette6387]

Awesome repair. Yea as long as your happy with your repair that should be all that matters. Any time you can repair something its great and a repair that cost no money is perfect. Cant shake a stick at that for sure. Thanks for showing it. Love and prayers to you and your family. Love ya Brother !!

[@Throckmorton.Scribblemonger]

It wasn't fully repaired and that box of capacitors wasn't free.

[@edgarcornette6387]

@@Throckmorton.Scribblemonger Keithley 2302 battery simulator was fully repaired with a free lcd module from his stash.

[@Throckmorton.Scribblemonger]

@ This video is about the repair of the VFD, it literally says it in the title. The VFD wasn't fuly repaired.

[@petesapwell]

Feel I should explain the ‘getter’ (the shiny mark inside the VFD) when the device is manufactured a little pan (under where this mark is) is filled with the inactive getter material, then once the vacuum is pulled into the device and it’s sealed the little pan is heated by induction, this evaporates the getter with then reacts with any remaining (unwanted) gas within the envelope, this leaves the mirror effect on the glass as the getter material cools. It then will continue to absorb over the life of the device as no sealed system is perfect, and if the mirrored area appears white then that’s a good indication that the sealed system has failed.

[@tundefodor5684]

nice video again. Thank you

[@dougobrien2840]

Love this stuff always learning something .Cheers from Roma Western QLD

[@4zims]

LCD for the win!

[@khangaudio399]

❤❤❤

[@volvo09]

So much more legible. VFD's are cool, but that one was super dim and crappy. LCD looks great.

[@Chriva]

I think you made the right call sticking with the LCD. Pretty sure we've all endured the joy of burned out VFDs in microwaves, cars, test equipment.. Beautiful to look at but man is it a horrible tech 😂 .. Would be cool of you replaced the polariser to invert the segments tho 😉

[@monkev1199]

A blue LCD might look better as well

[@zaprodk]

@@monkev1199 Blue/white LCD's look so damn cheap! - And the contrast on them is "meh" at best. I absolutely prefer the white/black or yellow-green/black displays.

[@coriscotupi]

You know what they say. It's always a capacitor. Which is of course an overstatement, it's a cap problem only about 95.7% of the time, at most.

[@SalvoMorina]

I work more or less every day with VFD...no one has issue with logic, all not working items have issue with the "high" voltage power supply, generally with output capacitor. As usual, very godies video !

[@jrnovosel]

It’s a good feeling when you can use something out of the junk bin. Especially if it’s been in the bin for a very long time.

[@Xaelloss]

Obviously, you should just have begun by replacing all the caps on that board in the first place. Can't go wrong with that approach!

[@DanBowkley]

Works okay at no load, goes spastic as the load increases....yup. The high ESR pulls the voltage down as it draws more current. It was probably resetting the driver chip every time it tried to power itself on. It occurred to me, would Keithley really use a VFD module from that supplier? I'll bet you half a pound of smoked brisket that isn't the original display, someone already replaced it once. VFDs are gorgeous though. I love the old school look of them.

[@EEVblog]

Probably right on the border of some threshold, and the subtle difference in the cap pushed it over the line.

[@mihaiachim5299]

@ 12:30 I can’t trust caps in kits 😅 + I try to always search for bigger casing caps for replacement … they are more reliable 😊

[@rodrigomaero]

Gotta love a free repair, that’s why I keep lots of old stuff. The missus is not very happy about it though

[@OzyWizard1973]

Well done.

[@coldfinger459sub0]

I just learned something about tantalum’s black stripe today. I even went through three semesters of Electrical Engineering, all the basics before Covid hit, and I never went back.. but I’m out of all the books and even papers about capacitors I read. I did not know the black stripe means it’s positive on a tantalum.

[@EEVblog]

Trap for young players

[@michaelhansen8663]

New VFD for the win

[@derx6666]

I noticed on 4:30 a small tin blob/ball between the legs of the main chip. Almost halfway (bit to the left). On every shot where it didn't work it was still there, but on the last shot (when it worked) the ball was gone.

[@EEVblog]

Interesting. Might not be conductive

[@d.j.wiendels6572]

The output cap has a higher voltage rating. voltage, temp and lifetime rating are somewhat interchangeable, that's why it lasted longer

[@rocketman221projects]

There's also very little ripple current on it. The anode current on a VFD like this one is only a few milliamps.

[@nutterts]

My objective rule of thumb, if a tantalum isn't on fire, it probally didnt fail. Glad to see it proven once again! ;)

[@peterferguson2344]

Talking of junk bins,, I've just sat around and put together a little speed control circuit for an 18vdc motor from parts that have sat unused in my junk drawer for years 👍hoping to make a mini lathe to turn my own fishing floats 🙂🤞

[@iamdarkyoshi]

If this was mine, I'd put the original unit somewhere firmly attached inside the case if there's room. I do the same with PC case blanking plates and modular power supply cables. Future me has thanked past me quite a few times for stuff like this :)

[@khangaudio399]

❤

[@TokyoScarab]

Remember, it's not hoarding if you need it eventually 😁

[@bobweiram6321]

You can take an Xray and see if the seal has been compromised. X-rays don't penetrate barium well.

[@mihaiachim5299]

@ 11:00 I always twist them off …I never desolder them 😊 - a good advice from Mr Carlson’s Lab channel 😊

[@gorak9000]

It's always the caps (except when it isn't). So I was right yesterday on the other video!

[@InssiAjaton]

BOTH capacitors are ELECTROLYTIC! One is aluminum electrolytic. The other one is tantalum electrolytic. With the small difference that the tantalum one is SOLID electrolytic rather than the ultra reliable/long life WET SLUG (hermetic) tantalum electrolytic. I am not sure if the solid aluminum electrolytic ones ever gained enough popularity to remain in the market place??? Anyway, they were available at one time.

[@EdwinNoorlander]

There is also a nice OLED version. With black background en white numbers

[@tomki6asp]

Those smd electrolytic caps tend to leak, too.

[@TechSB3037]

Good ol' Capacitor spray and pray . lol.

[@electrodacus]

The LCD is just a better choice and I prefer the green over blue.

[@sirtra]

Oh so that black corner is not a burn mark but normal?! In one of my cars there's a VFD clock which intermittently doesnt display, i took a look one day and saw the black marks on the screen and just assumed it was related so didnt bother diagnosing anything further. Now i'm thinking it's a similar fault as this and going to have to pull the dash apart to take another look.. which makes me simultaneously happy and sad 😆 You learn something new everyday...

[@EEVblog]

Yes, normal. But usually kept out of the visible product viewing window.

[@rocketman221projects]

That's the getter. Every vacuum tube has one or more of them. It absorbs any gas that the vacuum pump couldn't pull out during manufacturing as well as any outgassing that occurs during use. Silver or black is good, chalky white means air got in and it's dead.

[@zaprodk]

Burn? Nothing to burn there.

[@sirtra]

@@zaprodk when electricity is involved there doesnt have to be anything for there to be a scorch/burn mark, an arc is enough

[@ON8AD]

Do the "high voltage rejuvenating"-part. For science! 😀

[@gendragongfly]

Careful, that sticker may be loadbearing 😆

[@mrnmrn1]

21:31 At cerain angles, you can see characters burnt into the display. So at least part of the brightness drop comes from phosphor degradation. Maybe this is not a very high quality VFD after all. Yes, it might have been on 24/7 for years, so does my mini hifi since 1997, and no burn on the VFD. The brightness is not the same as it was, but still usable. Some Japanese VFDs have incredible lifespan, any other MFGs are unpredictable.

[@Master_zzz]

Have you checked the heating voltage? The VFD has heating wires... If the voltage drops, so will the intensity.

[@OmarMekkawy]

Oh Oh Murphy was sleepy again today!!!. Was that a coincidence? 😂😂😂😂😂😂

[@JayCras]

Its testing my memory but there is a brightness adjustment. Also a getter is to absorb the last bit of oxygen when its sealed up. And if you don't want the VFD? ;-)

[@kostasantoniadis5451]

VFD REPAIR 3 - Dave decides to unsolder again the display in order to replace it with a OLED compatible he just found!

[@teslatrooper]

Screw tantalums, all my homies hate tantalums. I was suspicious of that one from the start.

[@hans429]

Dont forget, it draws more current wen it shows a text, vs in idle, keep it in mind, wen measuring on the Voltage converter

[@EEVblog]

Yeah, maybe some subtle reset threshold was being hit.

[@Throckmorton.Scribblemonger]

2:22 I have never seen an SMD electrolytic capacitor with a split in the top; they use a different type of vent. 6:19 That doesn't have anything to do with it being a Tantalum cap; it's the package (round vs rectangular) that dictates whether the black stripe is on the negative or positive terminal.

[@roy2689]

I think it looks nicer with LCD

[@ChainShinra]

Would inverting the LCD maybe pose some better compromise maybe? Seeing that the filter is obviously made for darker displays. As much as I love VF Display, if it's just too dim there's no sence in continuing to use it, I absolutely concur.

[@anthonydenn4345]

Yea the inverted LCD would somewhat resemble the VFD light output. The digits could be lit up from a choice of colours also. Red, green, blue, yellow, white etc.

[@EEVblog]

Yeah maybe, but not worth the hassle, I already like it as is.

[@floodo1]

the green backlight has a classic look imo. None of this blue or white backlight (-8

[@landspide]

Surprised it wasn't Noritake.

[@DrFiero]

Wrap the original VFD up in a paper towel (etc) and leave it taped inside the case... then if a "future dave" from 2125 wants to go mega retro they can!

[@bobdun918]

I would still keep that vfd as a serviceable backup, ya, it is not as bright, but it could be usable for quite some time. Now ill see if I can sort out the missing segments in my microwave oven vfd.

[@EEVblog]

Yeah, it goes back in the display junk bin

[@alexmirica]

I clicked Like before the video began. For me it was guaranteed to be top notch! Dave style. Edit: I also replace the CRT display on LCR meters at the company where I am working with LCD ans Raspberry Pi as framebuffer generator and voila No regrets or nostalgia rubbish, Now it's simply better than original display technology, LCD vs VFD or CRT.

[@rohitkhanna4487]

I do like vfd displays however Keithley in particular uses VFD displays simply to promote planned obsolescence as vfd displays become dim after finite hours I have a keithley 2000 dmm usable but fairly dim vfd which is hard to find.........

[@nutsnproud6932]

I would have used a small potentiometer where the resistor went.

[@RabidBadger_]

Come on, Dave. You have nothing to lose, try the high-voltage rejuvenation.

[@guytech7310]

Yeah. use a full megavolt! It will be really, really bright! /joke

[@maItre_gonzo]

For "hitorically accurate" restoration you would need to fit a VFD, for a repair just use the LCD, better choice long term. That's all the difference between restoration and repair.

[@guytech7310]

You can still buy the same VFD from mouser or NewHaven: Changed the model number slight to M0216SD-162SDAR8

[@IvyMike.]

I thought the getter scavanges any gases left over from the production process.

[@zaprodk]

It does.

[@darrylr]

I'm waiting for the teardown of the capacitor.

[@ianstorey1521]

I haven't yet seen a polymer cap explode - hint, hint

[@crisjdsp]

Like , recife - Pernambuco, Brasil !

[@MSP_TechLab]

15:50 any arduino with lcd example sketch would allow to test that display. Why to bother with soldering/desoldering?

[@khangaudio399]

❤❤❤ tuyệt vời From Viet nam send best wishes to you Hello everyone .I wish you happiness health happiness and success in all fields. We invete you to watch the video of repairing and restoring my cassette radio .Cassette radios are beautiful memories of childhood .That's why I love cassette radios very much .Every day I repair and restore old broken cassette radios When they work again I will be very happy The fun is increased when you are interested in antique cassette radios .Thanh you very much . I learned a lot when watching your videos .Sincerely thank Youtobe for bringing us closer togeeter .Sincerely say goodbye ❤❤❤❤❤

[@GuoFuTseng]

Would the waveform be different if put a constant load on the boost converter output?

[@paulodagraca3469]

I wanna bet that Fran is not going to like the new LCD display 😮

[@WereCatf]

Me likey repair videos! Do you got any more fun gadgets to repair, maybe even some fun retro gadgets?

[@timturner7609]

As long as you're throwing it away you might as well have a go rejuvenating

[@arongooch]

Anyone else think that LCD backlight LED current is a bit too high? I wonder if Dave dropped that current limiting resistor too far?

[@dimmog]

Btw, If you have a 53131A or 53132A frequency counter in the lab with a dim VFD, I can send you a drop-in LED display replacement.

[@EEVblog]

I have one, haven't powered it up in a long time...

[@dimmog]

@@EEVblog Ok, I sent it to your mailbag segment.

[@duingstuff]

Saw the thumbnail and thought he made a mini wheel of fortune board.

[@pomprocks]

VFD looks 10x better than any LCD

[@EEVblog]

Unless it's too dim and then it sucks.

[@joseoncrack]

It looks cool, but I don't know about better. It's fine when it's bright enough, otherwise not so much. LCD (purely reflective) has much better contrast - but downside is that it needs frontlighting unless in a very well lit environment. Color displays with backlight can be cool but not as readable and often have a shorter lifespan. OLED has good contrast but requires very bright panels for use in sunlit environments (or even just bright artificial light), and also tend to have a short lifespan.

[@rocketman221projects]

They look much better as long as they aren't burned in or worn out.

[@guytech7310]

@joseoncrack VFD have better viewing angles (easier to read from the side since LCD rely on polarized filters. I am guess that the VFD was only 7/24 for very long periods, causing problems with the caps & dim display.

[@johnsonlam]

Agree to Dave, LCD did look better and longer life, but it's nice to know where the problem is, a good lesson.

[@gorak9000]

emissive bright characters on dark background is always easier to read than the LCD dark characters on a bright background. That's why people were telling him to get an LCD (not OLED) that as the bright white characters on a dark background, rather than the standard dark characters on green. They're actually the same LCD's, just with the polarizers flipped the other way

[@EEVblog]

@@gorak9000 Yeah but why would I pay money for a display when the juk bin green one is already very readable?

[@paulmcgrath2175]

The labels on newhaven displays are always peeling off.

[@jeremiefaucher-goulet3365]

I'm guessing it didn't show well on camera, how dim that VFD truly was. Didn't look that bad at first glance.

[@zaprodk]

5:14 - No it's PT, Princeton Technology :)

[@alexv3780]

It's not the caps. It's not the caps, right? It was the caps.. (every single time I try to fix an old device 😂)

[@guytech7310]

Is that why people get mad when I type in all CAPS? /Joke

[@BillyONeal]

Tantrum cap strikes again

[@alex_capone]

I thought it was gonna be about the other kind of VFD lol

[@Veso266]

Why dont u buy a replacment VFD?

[@jonathanreedpike]

You need a radium booster.

[@ardufreak6973]

Do I hear an "it's always a capacitor"?🧐

[@ralphj4012]

Meanwhile, the imminent short between pins 94 and 95 of the IC (4:34 and 15:07) was slowly and surely drawing its plan against you, ho, ho.

[@usagold8]

Those SMD electrolytics always seem to be a problem. I had an old Synology NAS that wouldn’t start up, the problem was easy to diagnose as the capacitor was making a terrific hum you could feel with your finger.

[@ijapsdjhkahbefajldas]

You should practise soldering more 🙈

[@piotrrze]

Go for OLED!