AE#61 Repair Of A Tektronix TDS 340 Oscilloscope.

[@michaeljacewicz4892]

You sure di know what you are doing! I worked as TV technical Maintenance Engineer for 15 years. I just picked up a tektronix TDS 360 -similar like yours with the same problem. You gave mea solution to my problem. Thank You!

[@michaeljacewicz4892]

Replaced a .o1pf cap 1KV (C320) in the high voltage supply for crt. Turned on Scope scrn init and display came on. The original cap was smoked and burned black. . Screen came on again fine. Thank you,

[@Taylor_26GE93]

Just wanted to thank you for this, I have recently bought a TDS380 which had a similar issue where it just clicked on power on, traced it through to a shorted FEP16DT diode, my caps looked fine so for now I just replaced the diode, perfect! Working once again. I might go through the capacitors at a later date

[@STBRetired1]

Great video. I'm looking into buying a TDS 360 and your video has taken the mystery out of what inside the beast.

[@felixcat4346]

Thanks for posting. You allways follow the golden rule of choosing the things you want to repair carefully.

[@WaltonPete]

Nice repair and a handy little scope. I wholeheartedly agree with your sentiments regarding electrolytic cap replacement. Too many people jump to conclusions about 'bad' capacitors without realising that unless they have failed short circuit most caps still function sufficiently, even outside their specifications, to do the job they're intended for. It's often worse to replace an old quality cap with some generic brand than to leave well alone, as well, which I've seen some people do on KZbin!

[@troutrou0]

Nice repair... have one of these scopes, a TDS 310 (exact same scope, just lower B/W), came with the GPIB card though... and also with a Power supply problem... and no schematics as you said. Was working on that PSU as you did, a year ago, then I was poking around the primary side, watching signals in/out of the PWM chip.. scope probe slipped on the chip pins and an impressive fireworks erupted, as the mains 400V cap burst into flames, preceded by a massive "BANG"... almost had a heart attack, jumped off my chair and ran for cover ! LOL. Now there are a few burnt/vaporized components around the PWM chip and I can't even replace/fix them because of course I can't identify them anymore, no schematics, no parts list... :-/ I love these old TDS 300 scopes, but their third party/schematic-less SMPS is no fun to work on. I don't like to be defeated though, so some day I will probably get back to it... and ask someone with a TDS 300 to help me identify the components I need to replace, so I know what to order... and resume the troubleshooting where I left it before the accident happened... Vincent Trouilliez

[@jukeman57]

Just found your channel. Terrific video. Very gratifying repair. Thanks.

[@MegaQwerty2000]

Nice video. I have the Tektronix TDS 360/200Mhz o-scope with floppy drive. So it was good to see this model covered.

[@felixwurm1467]

I have a 380 with 400MHZ , also with Floppy Drive nur sadly Not wird the Option 14( in Card).

[@1959Berre]

Nice catch. Though I prefer my analogue Tek 466 because of its perfectly stable and fine trace, this looks like a nice machine. Tek rules.

[@Hackinside]

It seems to be a common issue on all TDS 300 series. I fixed 2 different models with the same component replacement.

[@leisergeist]

I had a power supply clicking like that once, and only those under like 40 years old in the room could hear it! That was kind of interesting, it was one of those frequencies like a dog whistle or something.

[@tjsogmc]

No bossman, don't apologize for selling something like that for X price. Your labor is worth something. I just bought an HP1740A for $120 in working condition, but I went through it anyways. I found some dry and broken solder joints on the power supply, then gave it a calibration test (it was actually good and didn't need adjustment). So would I sell it for $120? No. I put 2 hours of my time and expertise into it. I would charge $200 or $240 and the buyer would be getting a like-new scope that will run trouble-free for another 40 years. Time is money and money is time.

[@artifactelectronics]

I hear you, but in my experience buyers are only interested in what you paid for the device. Labor and parts are considered to be free.

[@jimcastillo8950]

You stick to your guns. The viewer out there should consider what a technician hourly rate is also...................... Time is money......... Great videos

[@judges69]

Good video, thanks

[@gordonwedman3179]

Handy when you have another copy of the same component to compare readings with. Hope the PS in my Tek 2710 spectrum analyzer is this easy to fix.

[@MuellerNick]

Nice scope, nice job! I actually opened such a Dallas POS with a Dremel and replaced the battery. :-) Yes, that worked.

[@benbaselet2026]

Did you manage to retain the RAM contents too?

[@MuellerNick]

There was no need to try it. It was for a laptop. But with some planing ahead, I think it can be done. Might look a bit ugly afterwards. :-)

[@TheDefpom]

Nice repair.

[@viggosimonsen]

The fan is still quite noisy on these scopes, even when dusted off I just purchased a used TDS 320 scope, and I plan to replace the fan with a much quieter PC fan I have in spare - which even seems to push more air

[@MichaelRusso]

Yeah, I buy something for $35.00 and put time into getting it and working on it + my over head (food on table). You bet I am not selling it for $35.00 and if you don't like that fact, go buy one on Ebay.

[@martinda7446]

Holy shit - You shouldn't have to explain this to people...Some people are just silly. Anyhow you can quite happily sell anything you like for any price you like - That's how it works, If its too expensive nobody will buy it. etc...

[@martinda7446]

@@jadielbenton1466 Did it?

[@martinda7446]

@@jadielbenton1466 You both joined YT on March 5th funny that.

[@SidneyCritic]

We used to cast engine manifolds and paid $30ea. When people found out they wanted them for $30, totally ignoring the $5K patterns and machining. What was even more stupid was that we were selling them for $130ea, and the next cheapest was $200. I would like to see them go to Apple and ask for a iPhone for the price they are made at, and watch Apple laugh at them.

[@jonka1]

All those people who want to buy your gear for what it cost you wouldn't say that if they were selling their own repaired stuff. Oh that would be different -- "look at what the are going for on Ebay" they would say.

[@dr.shtirlitzz]

I have one but model is 340AP with the floppy drive and thermal printer. Good device for it's price

[@leoashrae4199]

Those Dallas DRAM chips are one of Tektronix few serious mistakes. If the battery isn't dead now, it will be shortly. And, when the battery does finally die, the calibration data stored in the chip will be gone. The only "proper" fix I have found (which worked for my 2440 scope, at any rate) was to replace them with new (I found them at Mouser) and then do a complete external calibration. The caveat is that a very quick pulse generator is required to do the calibration. If you are fortunate enough to have one (or know a colleague who will lend you one), the calibration procedure isn't very difficult. If you don't have the tools, the calibration cost is more than the scope is worth.

[@the8bitbarn836]

I have a TDS 340A with most of the options I haven't even looked inside works great! (Knock on Wood) But I have a TDS 430A with all the options speaking of which the Option Knob quit working on the main panel so I think I will have to dig into that one... Any Ideas on that one would be helpful. So many things to repair and yes all of the above Items where purchased on E bay as junk or repairs. So you get what you pay for and all of these devices need recapping!

[@glenng.8254]

Lol. You were playing cw on the fuse test. ..._._. Funny. I do the same thing. 73 ve7cpr

[@MultiBwee]

Thanks for the video, got the same scope , mine blow when mains fails , on checking it fuse was blown , replace and it blew again , open it up and varistor is blow , don't know its value , maybe you can help since yours is still intact

[@dakata2416]

How good is this scope? I'm thinking of getting one, but I'm split between the TDS340 (multiple options installed) & TDS360 (no options). Which would you recommend? Great video!

[@artifactelectronics]

The 360 is twice as fast as the 340, but if 100 MHz is enough for you I'd take the optioned 340.

[@dakata2416]

@@artifactelectronics I am planning to work on some audio & smps stuff. I was also thinking about 340 because of the FFT option. Thank you for the answer!

[@aaronblair9583]

man i could use one of these. my Tek 564B works great, but sadly it came with TDR sweep and sample modules instead of standard scope plug-ins. I cant complain for an $11 scope though, it looks pretty on the workbench... still, gotta learn how to use a scope someday. luckily so far my repair ventures have only required a tube tester and my fluke.

[@aaronblair9583]

Does anyone know what in the world i would use a TDR for? checking coax cables?

[@STBRetired1]

Here's something I just noticed as I was narrowing down my selection of TDS 360's to buy - one has a plastic carrying handle like on yours and one has a metal handle. Do you know which would indicate a newer model oscilloscope? I can't read the Serial Number on the one with the metal handle. The plastic handled one is B018480. I just noticed in another of your videos (AE#4) that the TDS 460 you are working on has that metal handle, too.

[@PaulHigginbothamSr]

Artie: if these dolts don't understand that time is money then there is no hope for them. I would charge as much as the traffic will bear because that is the nature of capitalistic market forces. Since we are not yet a Communist entity, (which I pray never happens counter to all our current teaching establishment forces), then your time is worth something and your deductive reasoning approach can be entertaining for me.

[@artifactelectronics]

Some people don't want to pay for labor because they view the labor of others as intangible. Yet these same people happily collect a paycheck for their own labor. Software piracy is a good example of this.

[@SeanBZA]

Would not replace the diode after all, just leave the tried and tested upgraded part in there. Less likely to fail running at lower current relevant to the spec.

[@FireballXL55]

I would as the original is metal tabbed with a junction to case of 2.2 deg C/W compared to the plastic unit of 5 deg C/W. The original is also rated at 200V PIV and the replacement 150V.

[@SeanBZA]

Voltage not really a worry, likely only sees 50V at most in the reverse direction. Thermals the limiting factor is the heatsink, not as if it is on an infinite heatsink at 25C, that chunk is not big and not going to run cool anyway. Biggest thing is the peak current through the original was probably around 15A on switch on, and peak per cycle was probably around 5A, so having a part capable of 3 times this means more, bigger die (leakage it's a Shottky so leaky anyway) and thus a lot more robust part. Likely did a 5v rail, or a 12V or 24V rail only. The high current rails in this scope, with high voltages and currents, are in the CRT section separately. Failed probably because of slight winding differences meant one side handled most of the current and ran at the edge of the repetitive current envelope. Larger die, lower slope resistance and it probably will run cooler anyway at the current here.

[@FireballXL55]

I doubt it is 24V rail as the CRT looks like a 15mm neck so requires 12V in both heaters and deflection, could be done with 24V deflection but wasteful. I was just looking at it being switch mode and in europe it would run off 230/240V so the on duty cycle could be as low as 20% and the PIV would be higher not counting any ringing etc.

[@davidgeltz7604]

Did you know that the end of the fuse holder you removed can store a spare fuse in it.

[@t1d100]

Great repair! NFM can show you the tricks to changing out that IC that has the built in battery... IIRC, he grabs the firmware, while the IC is still in place. Then he flashes the firmware onto the new IC. Then, he attaches a battery to the power pins, to carry the power over, while he removes the old IC and installs the new one. IIRC, too, he always changes out this type of IC, even if it tests as good, because, if the battery dies, it is a big problem to get things going again. Hope that helps... kzbin.infovideos

[@fullwaverecked]

I scored a tek 317 1959 scope, seems to work a treat. Am I going to sell it for $10.00? No thanks. You can go ffffind one your self.

[@rogert151]

does this scope have a probe attenuation setting, or does it need those probes with pins near the bnc ?

[@artifactelectronics]

I no longer own it, but I think it had pins.

[@roshbodiya5855]

HELLO , I NEED SCHEAMETIC DIAGRMS OF POWER SUPLY FOR REPAIR POWER SUPLY UNIT. THANK YOU

[@artifactelectronics]

I suggest that you do a google search. There is a lot of info available.

[@netten2057]

where can i find the fan of the power supply

[@artifactelectronics]

Fist note the required voltage and current rating, and then get the exact fan case dimensions including hole offsets. Then head over to eBay, Ali Baba or whatever and start searching.

[@netten2057]

@@artifactelectronics a lot of thanks !!

[@harbselectronicslab3551]

People are dumb arses....... just because you got it cheap or even free doesn't mean the next guy will get the same luck............they are just to thick to understand business.........I mean would they go into McDonald's and demand a burger at cost price......sheeeshhhhh.

[@boonedockjourneyman7979]

Why do you bother talking about the business of KZbin? Forget about it.