Analog oscilloscope repair 2 - Capacitors, ESR, leakage current

Рет қаралды 17,706

10 ай бұрын

1982 Tesla BM556 analog oscilloscope repair continues. Now I've fixed the brightness control problem. It was caused by bad capacitors in the high voltage switching power supply, which also produces the CRT heater voltage. Now the heater voltage is stable, no more fluctuations. Measuring and explaining the ESR of electrolytic capacitors and the leakage current. In the next episode, I have to fix the bad synchronisation.
The next episode:
• Analog oscilloscope re...
The 1st episode:
• Analog oscilloscope re...
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Пікірлер: 78

@iamdarkyoshi 10 ай бұрын

Excited for the next one, love these long in depth repairs

@d.k.9406 10 ай бұрын

¡Exact¡!!!!!!!!!!!!!!!!!!!!¡

@TechGorilla1987 10 ай бұрын

Your soldering technique is the most Eastern European-looking thing I have ever seen. I get a kick out of it and it looks solid AF.

@8o86 10 ай бұрын

just curious -- what in particular makes it eastern european looking? :) (surely enough, my dad has the same iron and technique and we're from czechoslovakia)

@TechGorilla1987 10 ай бұрын

@@8o86 The sheer stout utilitarian look. No frills but way overly effective. The rosin box looks military. His trigger finesse is excellent. I meant it as a compliment.

@mernokallat645 10 ай бұрын

@@8o86 Probably because many people in the west would't even bother to repair something, just discard it a buy a new item.

@cambridgemart2075 10 ай бұрын

@@mernokallat645 No, because most people in the West use pen style soldering irons for electronics work.

@Fluorescentlamplover 10 ай бұрын

Best guy in the world's universe to make something/build sometimg Edit:,Thx for this much likes guys!!!!!!!!!!!!!!!!!!!!!?!¡!!!!!

@Fluorescentlamplover 10 ай бұрын

Edit:Thx for this much likes guys!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!¡!!!!¡!!!!!!!!!!!!!!!

@annaplojharova1400 10 ай бұрын

The higher capacitance reading of leaky capacitors usually comes from the way how the multimeters use to measure the capacitance (charging by a small current, measuring the time to a fixed voltage). Most do not feature any leakage compensation (e.g. doing second measurement by discharging it back to zero). And regarding the capacitance: The 47uF is essentially the same as 50uF, as well as values like 56uF or so. The rated tolerance uses to be -20/+100%. The reason for odd value formal ratings like "56uF" is not because you would need that difference in capacitance, but to ensure a proper ESR and ripple current rating is maintained, even when some aggresive but not that technically savvy purchase officer tries to save pennies by switching to cheaper components. The trick is, the odd value is available only with the high ripple current/low ESR format, so he won't be able to purchase a cheaper general purpose type for thar. The 15/33/68 are used for generic low ESR, the 12/27/56 are used only for really super low ESR/high ripple current rating. Of course the standard 10/22/47 values are available with those ESR/RC specs too, but when as a design engineer, you want to ensure no bean counter moron would swap them for cheesy spec type, you just specify such odd value instead. The same reason is behind those crazy values of feedback resistors (like 10k1), used as two of the same value around TL431 in 5V supplies, where any pair of equal resistance and similar ballpark values works, but you need them to be precission types to be really equal. The "10k" could be purchased even as 20% type (so may differ more than 20% from each other), but when you specify "10k1", the purchasing monkey would be able to find only 1% (or better), so you could be sure the divider will remain right.

@J.T323 10 ай бұрын

This dude is a legend .. .

@sajidmohammad3190 10 ай бұрын

The most detailed and informative videos on the earth are from you. Great!

@tajtrlik1111 10 ай бұрын

Ďakujem za ďalšie video z tejto série, musím povedať, že veľmi precízne odvedená práca a veľa užitočných informácií ohľadom elektroniky, radosť pozerať. Na ďalší diel s opravou časovej základne sa veľmi teším, predpokladám že to bude tiež veľmi zaujímavé.

@RODALCO2007 10 ай бұрын

You got the heater voltage nicely stabilized. Making good progress on this oscilloscope.

@Ale.K7 10 ай бұрын

Can't wait for the next part!

@beatrute2677 10 ай бұрын

Really enjoying this series man, good stuff

@MlokKarel 10 ай бұрын

Can't wait for episode 3 - is it the bloody tunnel diode (gone wild) or will it be something else? 😀

@michaelmurray3422 4 ай бұрын

Very nice job. Very Nice Presentation. You really know What you are talking about.

@mrnmrn1 10 ай бұрын

I would solder the fuse into the fuse holder on the HV PSU control board. I have the 120MHz BM566 model, and the high voltage was intermittant. The cause was bad contact of that fuse. I tried to bent the contact to make it tighter, but the it was still flaky. The metal is too thin and not springy enough, no matter how tight I bent it, just inserting the fuse loosened it up. Now it works, but I will solder the fuse into it when I will get around to do a restoration on the scope. The fuse holder is riveted to the board under the solder, so I won't bother replacing it. Mine is from 1987, and it has one of the dreaded brown bakelite-encapsulated Tesla paper capacitors in one of the 500nF positions in the HV power supply. It has a nice crack on it... Mine also has a ton of tin whiskers on the can of the Y attenuators. BTW, are you sure this is a switch mode supply? I would think it is a high frequency sinusoidal oscillator. It was more common in older oscilloscopes, because it is a lot easier to filter out the sinusoidal ripple than to deal with the lot of harmonics a switch mode supply produces, both conducted and radiated.

@Mike957 10 ай бұрын

Very nice! Your channel is one of the channels that inspired me to work in the electronics industry

@DiodeGoneWild 10 ай бұрын

Thank you for your support! I'm glad I inspired you ;)

@KeritechElectronics 10 ай бұрын

Lovely repair series - it's clearly going somewhere :)

@t1d100 10 ай бұрын

Excellent progress. I thought your wire work on the component pins was quite skilled = No joke.

@harrymartin1661 10 ай бұрын

Wonderfull as allways! Thank you very much.

@erikziak1249 10 ай бұрын

Top quality content!

@liam3284 10 ай бұрын

Something I learned the hard way, high leakage currents can cause falsely high capacitance measurements.

@Alexelectricalengineering 10 ай бұрын

Awesome 👍, love it!!

@HerrAlien 10 ай бұрын

I actually still have a similar soldering gun like yours - I specifically looked for one that keeps the copper wire in place with plain screws, and I found and bought one back in 2005.

@wolfrobben6914 10 ай бұрын

As said, please continue making these videos!

@DiodeGoneWild 10 ай бұрын

Thank you ;) I will keep making them.

@DerEnergiewendler 10 ай бұрын

Tech videos from a Vampire thats the good stuff

@dosgos 10 ай бұрын

Great scope fixing series! More cat please.

@snakezdewiggle6084 10 ай бұрын

This is great, thank you !

@MegaFoster86 10 ай бұрын

bloody interesting!

@braveheart9275 10 ай бұрын

Good job , thanks.

@marekmaslak8040 10 ай бұрын

1:00 That´s actually recommended in the service maunals of various TESLA pieces of equipment, so you won´t risk lifting the pads. 2:40 I love this, reminds me of my teenage soldering stationless self. Even having the exactly same soldering gun. Except I wasn´t doing such a pretty lead bending as you. My recaps are sloppy indeed.

@T2D.SteveArcs 10 ай бұрын

It was done in old radios and TVs TVs aswel for speed mainly, I do it in modern gear from time to time, theres nothing wrong with it at all..

@celsoneves2368 10 ай бұрын

Top show

@marcorizza274 10 ай бұрын

"Horribly bodged in" i want this on a t-shirt

@mendelpearl8066 10 ай бұрын

This seems heavily inspired by the Tek 453/454 scopes from the sixties

@andreastarp6583 10 ай бұрын

Danke!

@DiodeGoneWild 10 ай бұрын

thanks fot the support ;).

@d.k.9406 10 ай бұрын

Danke! Thanks to your Parents... We can now see.. You cleaning some electronics with your old toothbrushes 😂😂😂😂

@bmaj55 10 ай бұрын

Make a video about your tungsten lamp collection and turn them all on

@thisisdvd8094 10 ай бұрын

What does the "tv mode" mean?

@anonhollmuller4032 8 ай бұрын

Sync failure on my old one (after replaced some parts) was because balnce voltage ( sync) become 0.2 v too high May help ....may not......but i feel responsiible to tell :) Good luck! sorry my english declines;)

@kapegede 10 ай бұрын

The thing that disturbs me the most is the worn out protective layer on the display of your ESR meter. Would you mind to peel it off with some erotic music underlay?

@johncoops6897 10 ай бұрын

Why? The whole idea of a screen protector is to protect the soft plastic screen from scratches, so within a short period of time the screen would be permanently ruined. I always leave the screen protector films on, since it's stupid to remove them.

@rahulbhaskar4179 10 ай бұрын

Soldering enthusiast may get seizures....😂😂😂😂😂😊😅😊😊

@TechGorilla1987 10 ай бұрын

@17:52 - This reminds me of being a kid and flipping one or mums mirrors that had a magnification on one side and normal on the other. Little face. Big face.

@kieleccyelektrozomiarze 8 ай бұрын

When you make second part?

@DiodeGoneWild 7 ай бұрын

This is the 2nd part, but the 3rd part is hopefully coming soon ;).

@swsaber8199 10 ай бұрын

Next Megger Meter Please :)

@SuperSeanXXX 5 ай бұрын

Oh boy

@PeterMilanovski 10 ай бұрын

That 2.2μf 450V capacitor with the 7Ω ESR, how old is it? Panasonic recommends on their website to reform capacitors that are new but have been sitting around for a while.... I'm sure that if you brought that capacitor up to rated voltage slowly on a high voltage power supply, making sure that it doesn't get too hot (they usually get warm but cool down and stabilise which then you can raise the voltage again for another step until you reach full rated voltage) and it will be restored and display lower ESR.... Actually display good results all around... I'm sure that after being in use for a while, if you test it again, it should show less than 7Ω resistance.... You can test it out on another capacitor that is showing higher ESR than it should and you should see an improvement after being left at rated voltage for a few hours.... Anyway, love watching old capacitors being tested but sometimes new capacitors can appear to be worse than old ones, especially if they are old stock.... Looking forward to seeing the next video...

@DiodeGoneWild 10 ай бұрын

That capacitor is less than a year old, never used. Forming can reduce the leakage current, not sure it reduces the ESR. I'd have to try it.

@omniyambot9876 10 ай бұрын

@@DiodeGoneWildpls update with this, important

@PeterMilanovski 10 ай бұрын

@@DiodeGoneWild I would love to see that.... I saw someone else a while ago who got upset that the capacitor looked bad even though it was new and threw it out... He didn't try to see if it could be saved, he said that he got it from eBay and it's probably a fake... But I think that it probably had been sitting around waiting for someone to buy it... I know that that talking about reforming capacitors is a hot topic and people either agree or disagree.... I don't agree with reforming an old used capacitor, if they are dry.. you can't save it! And therefore you should never try to reform old capacitors but new old stock is okay... I use a Variac and a bridge rectifier through a μA meter and shunt plus a DC voltage meter and bring up old capacitors slowly and watching to see when they start to pass current... This way I get to see how it will perform under real world voltage... A switch and resistor makes sure that it safely drains the capacitors after the test.... It's a good way to test old capacitors and also reform new old stock.... I have various capacitor testers but this is my favourite way, it's like those old high voltage capacitor testers from the 40's and 50's from the American Heathkit and Elko brands but trying to get one of those from America to Australia is a joke! Shipping usually costs twice the price of the product and then there's import charges on top of that! And I thought that we were supposed to be friends? The Chinese are taking better care of my needs LoL... But anyway, thanks for the response! Love your channel! Always looking forward to seeing your next video!

@michvod 10 ай бұрын

@@DiodeGoneWild Forming usually increases the ESR as the capacitor itself is drawing less current. I am talking about the old capacitors that weren't used for decades, like from a tube radio or similar :)

@heno_3098 8 ай бұрын

@@PeterMilanovski It is common for 450V electrolytic capacitors. Try to compare the ESR of a new one for 400V with the ESR of a similar one at 450V and you will understand. This is apparently because the type of electrolyte for 450V types is significantly different from the electrolytes used at 400 volts and lower voltages. I myself compared it many times with several products of the same brand and also various brands and similar type, which did not differ in size or capacity and were freshly manufactured. And not one piece, but the entire series of 450V was the same, there was no reason to throw them away and there is no reason to suspect that they are defective.

@teslakovalaborator 10 ай бұрын

k 2:33 - to není "the lazy way", to je v návodu předepsaný způsob, jak máš ty součástky vyměňovat 😀

@DiodeGoneWild 10 ай бұрын

Opravdu? Už jsem párkrát někde slyšel, že ve starejch servisních manuálech tohle opravdu doporučovali, ale nikdy sem to neviděl na vlastní oči.

@teslakovalaborator 10 ай бұрын

@@DiodeGoneWild cituji z manuálu k BM574, strana 44: "Při výměně součástí na deskách s plošnými spoji není dovoleno pájení součástí ze strany fólie, ale je nutno postupovat tímto způsobem: Vadnou součástku odštípneme tak, aby délka vývodu nad tištěnou deskou byla co nejdelší. Tuto zbylou část co nejdokonaleji očistíme a na ni připájíme součást novou. Při vícenásobném zničení stejné součásti je vhodné zaslat přístroj do výrobního podniku k opravě." Ono to jde vidět i na celkové konstrukci přístroje, že jednotlivé desky jsou totálně zastavěné a vytahovat je z přístroje je malá noční můra 😆

@LawpickingLocksmith 10 ай бұрын

What did the cat suggest?

@SigEpBlue 10 ай бұрын

Every time I see that damned soldering GUN, it's like chewing on broken glass, while someone else squeaks chalk down a chalkboard.

@mp1454 10 ай бұрын

😀👍🏻💯👍🏻👍🏻👍🏻👍🏻

@makoveliprod 10 ай бұрын

What is "glass passivated junction"? Again I encountered aging semiconductors, two 4007 diodes in 0.5A 12V bridge rectifier got open circuit, wtf? Warming up with a soldering iron restores it for a while. The datasheet recommends using new ones 4007G (G means glass passivated junction) diodes, what this? This is a new technology for protection from aging semiconductors (from loosing internal connection)?

@heno_3098 8 ай бұрын

That's easy... Anything that is molded into thermoset or thermoplastic will eventually rot inside because it's cheaper, but this type of encasement becomes moisture tight over time. therefore, to this day, but also 60years ago chips for military applications are encased in ceramics or glass, it costs more but lasts longer.