AE#18 Tektronix 465M Analog Oscilloscope Repair And Checkout

Repairing a Tektronix 465M Oscilloscope. Dual trace, 100 MHz Analog. The electronic diagnosis and repair was simple, but physically replacing the faulty part got a bit more involved.

[@nogeek43]

I watched this video and my 465M was having the same type of problem with the trace. I replaced the same capacitor and lo and behold it was fixed. Thanks for doing this video as it helped me greatly. Pat in Louisiana

[@kenklwfly]

Fixed my own 465M after watching this video. The left edge of the screen was distorted. The 95 volt circuit was only putting out 76 volts, and the same capacitor was the cause. Now it looks normal and works well. Thanks!

[@danielmelendrez1616]

Great repair! Congratulations, Sir.

[@ronshaw80]

Tek scopes are great. I picked up a 2215A ( mid 80's, I think) for my bench, and it works flawlessly.

[@legpetruchka2124]

Assurément, j'ai regardé votre vidéo avec intérêt car je possède un TEKTRONIX 492P qui est en panne. L'accès aux différentes parties de cet oscilloscope s'avère plus "facile" que le 465M. En tout cas merci pour votre vidéo.

[@noakeswalker]

I am amazed that 89v rather than 95v and too much ripple could pretty much disable this scope - cheap fix, but a pain to get at ! The 465 was a great scope - I used them daily at work all through the '80s on UK MoD work. A good trusty workhorse. You seem to have lots available too ! Very nice to see them restored. I used the delayed timebase when looking at the waveform coming from DDS tape drive read heads, for eg. The feature you wanted to look at was always a long way away in time from the stable triggering feature of the waveform, so one way to do this is with a delayed TB. This is what you pointed out in the vid, but just thought I'd point to a real world example.

[@artifactelectronics]

I never recapped the whole instrument, so maybe the cap I replaced was the the straw.

[@hiteshsidar5352]

Superb scope ..

[@douro20]

Iwatsu a few years back made a very interesting 1GHz analog storage oscilloscope with digital controls and an LCD display. It used an actual microchannel plate storage tube and a CCD to capture its output.

[@rayburke4386]

I use to work at Tektronix on these scopes and the Vertical Module is fairly easy to pull out. You have to pull the vertical deflection plate leads from the board using needle nose or tweezers first, not just yank the board out, that breaks things. You don't need to remove the delay line screws to remove the vertical deflection leads, or pulling them from the CRT pins, the CRT pins are very delicate. You can see the leads by looking at them from the back side of the board or over the CRT. Then you remove the cable at the bottom middle of the vertical board and you can then remove the vertical module, to properly fix the vertical deflection pin. The horizontal just comes out by removing the rear screw and loosening the front screw, and disconnecting the power shaft, pulling up on the module.. (no deflection leads, they are under the CRT.) I noticed that the rear mounting screws were missing going from the vertical and horizontal modules to the rear support bulkhead, unless you didn't show removing or installing them. It seems that lots of equipment has missing screws, from people just taking things apart and not reinstalling everything correctly. Later Ray

[@fasthardware6293]

Can u help me troubleshoot my tektronix oscilloscope? My email is [e-mail]

[@viewer54322]

Artie, I know what you mean about the spray power being finnicky. Keep in mind if you need in the future: try putting contact cleaner in a syringe. If you need further reaching abilities, connect syringe to some tiny flexible fuel hose (like for a weed eater or chain saw) with a blunted needle attached to the end of hose. Cheers

[@InssiAjaton]

My use for the delayed sweep has been first and foremost to measure selected rise or fall times, especially when the only stable trigger came from another pulse. It also was possible that what I had to characterize was a glitch, impossible to directly trigger on.

[@xtraceex]

Have one of these, great 'scope. Also have a 453, which has a lesser bandwidth, but which is fine for the work I do. What I really like about the 453 is that it has an astigmatism control, which gives a nice sharp trace. Wondering why Tek did away with this control on later 'scopes...

[@kevinmccarthy8003]

Very useful and many thanks for a no-nonsense view around the inside of a 465M (Same as the one currently dead sitting on my kitchen floor, staring at me pleading to be fixed). I used this scope in the 70s during my test job in underwater weapons guidance systems and was amazed by the delayed sweep funtion. It made my job so much easier being able to quickly focus in on rise times and detect ringing caused by "lazy" capacitors and slow inductors. A very useful function then and hence my ebay purchase of a dead 465M. I think I may if succesful, call it Lazarus?

[@artifactelectronics]

The 465M is not that complicated inside, so I'm not sure if it qualifies as a Lazarus. Since it's dead it's probably the power supply. But only you can tell.

[@RingingResonance]

One technique I found for cleaning pots as using 91% isopropyl alcohol, working it in, and then leaving the part or instrument in a warm dry place or if small enough inside a dehydrator.

[@1959Berre]

Nice catch. There is no substitute for a fine trace on a CRT.

[@tiggywinkle1000]

Classic fault finding at its best !

[@srtamplification]

You can also use the calibrated scales on the delay to get a more accurate time measurement that thus a more accurate frequency measurement.

[@ostermann6176]

Respect Arti :thumbsup: !

[@ilanmower]

Nice!

[@Kennynva]

Do most oscope's have the delay sweep function???

[@bobmustari6087]

If you don't know them you should get familiar with CAIG LABORATORIES. They have a contact cleaner in a nail polish type bottle with a brush cap that would be ideal for your technique of pot cleaning.

[@bloguetronica]

Hi! What is that coil of cable? A coaxial delay line?

[@basinstreetdesign5206]

Exactly

[@abrahamrosas7159]

I have the scope, I had the same problem the F558 burn when I turn the scope, I reading about this issue and it occurs when the voltage of +95V is unregulated and I don’t any voltage in the test point of +95V. I think that the voltage multiplier is burned :( or the CRT is bad.

[@Antno]

I ordered the same one hopefully mine works it may need calibration though

[@artifactelectronics]

It will need calibration. I used it the other day and the DC calibration was about 10% off.

[@bigalejoshileno]

I'm getting 11v at the 95V test point, and there's also a broken fuse there (that 250mA glass tube fuse). Can be that the same capacitor fault?.

[@RingingResonance]

Could be. Bad capacitors are common on the 465 scopes.

[@mohamedelghanam1942]

Hello sir Can you help me how i use it My friend give me it as agift but i don't know use in test components

[@artifactelectronics]

The full user manual is available online. If you study it a bit you'll be using it in no time.

[@jadney]

5 minutes of information packed into 31 minutes of video

[@fasthardware6293]

Hello sir. Can u help me fix my 7104 oscilloscope

[@Paul-gz5dp]

First thing is get yourself a copy of the service manual, and if you have a multimeter, another scope, and a signal generator. You will have what you need to find the problem. Most of the schematics show what the waveforms should look like at each point shown on the schematic. Also before you get that far look for open fuses, and burned or broken parts. If you are near me perhaps we could work out something to get you up and going. I'm in Southern California, and there are some things I can do that others can't and there are things that I really can't do that most other people can.

[@fasthardware6293]

@@Paul-gz5dp Thank you for the reply, yes I got the service manual and following the instructions on the manual I have checked all the Low voltages and they are all with in specs, However I need to check for AC ripple, have not done that yet . I'm in Los Angeles, if you would like to help out, thats great.. I need to test the Plug IN with another working Unit. Thx

[@vukanbojovic8073]

I received 475 as a gift, but the man who gave it to me told me that he switched the input voltage switch by mistake instead of 220 to 120 watts. it was short, maybe 1 sec and he turned it off. I never repaired the power supply and oscilloscope and I did the same and in the part where the two elements are (I think they are transistors) I found "blackness" on some element that I did not touch. I am asking for help, I live in Serbia and there is no one here who could fix it. I have more than 30 years of experience in serv.electronics, but I have never serviced oscilloscopes, so I am asking for your advice and help. Thank you in advance Vukan

[@artifactelectronics]

When you power up a device with 220V when the range selector is set to 110V all of the transformer (T700) secondaries will produce twice the rated voltage and, at a minimum, cause damage to the power regulator circuit. I would disconnect the regulator circuit from the rest of the instrument and then check if you're getting the proper voltages. Start with the rectifiers (CR721, 741) and work your way to the right. Since the unregulated voltage rails were doubled expect to find components tied to these rails to have failed. Good luck, and don't forget to check fuse F700.

[@vukanbojovic8073]

@@artifactelectronics thank you for your quick response, I will listen to the advice and report the results. thank you very much again

[@christian56311]

I have the the same o-scope and need it repaired. Can I send it to you for repair?

[@gowdsake7103]

Good job but honestly you need to speed up things it gets a litle drawn out. I mean 30 min to change 1 capacitor

[@bucheronix]

IPA : Isopropyl Alcohol

[@warplanner8852]

"..could not determine what state it was in.." Per your future 465M video, wasn't it in the state of Utah? ..nuk..nuk..nuk..

[@dedskin1]

you must be joking , 1 cap change and it works , what waist of time