Tektronix 2440 Oscilloscope Repaired- Part 4

By on October 9, 2015



tektronix scope repair

 

 

 

 

 

 

 

Here are the previous article:

http://www.jestineyong.com/tektronix-2440-oscilloscope-repair/ (Part 1)

http://www.jestineyong.com/tektronix-2440-oscilloscope-repaired-part-2/

http://www.jestineyong.com/tektronix-2440-oscilloscope-repaired-part-3/

Today I opened the already completely repaired 2440 Tektronix Oscilloscope again to try and fix some of the remaining FAIL errors. (FAILs which were mentioned in the already published 2440 Repair articles part 1 to 3)

I wanted to start with the 3000 FAIL concerning the U664 SRAM on the A12 Board. So I checked the Boards with U664 , and U424A by touching all components with my fingers for hot spots again. And I was trying to test some of the signals on U664 with Probe Channel 1. But to my surprice at Start-Up/Powering Up the 2440 Tektronix Memory Scope, all of the 3000 Fails had gone.

Something had changed because a 6000 FAIL message “ CKSUM NVRAM* ” had added itself to the FAIL list. And that part has not been there before and could mean an empty Lithium Battery problem.

And because my previous message at address 3000 had gone I took another try in Fixing the remaining errors by the Scope’s Built-In Self Diagnostics. But I first closed the Oscilloscope again, so the FAN could effectively keep all components from over-heating.

After a 10 minute or so warming up time with the Oscilloscope case closed (when the warming up first warning on screen disappears from the screen the warming up period is complete) the SELF CAL routine can be started by first pressing the MENU OFF/EXTENDED FUNCTIONS button. (like explained in the previous 2440 repair articles).

And after some time RUNNING, the PASS message appeared above the SELF CAL choice on the screen.

And next I did the same with running the SELF DIAG choice on the screen. And to my happy surprise also this test had automatically PASSed itself after RUNNING.

So when I now startup the 2440 Scope by pressing the ON/OFF Button, the “running self test” message only briefly shows on the screen, after which every Diagnostic Test comes up being all PASSed.

And the Tektronix Scope has completely fixed and Calibrated itself!

Following photos prove that the 2440 is completely working as it was since 1988.

tektronix scope repair

On previous photos the SELF CAL diagnostic has passed. (I better wait until the scope gets Warmed up before continueing with the SELF DIAG. By pressing the button under that text on the screen.

repair scope

Photo above clearly proves what a great piece of Hardware Tektronix really is!

I just saved myself $600 dollar on Calibration Costs by letting the Scope run its own Built-In Diagnostic!!

Next photos show that the 2440 Oscilloscope is ready to read the signals on Channel 1 and Channel 2.

I earned my Coffee break and placed my cup on the sturdy Tektronix Machine.

3

repair oscilloscope

repairing scope

This concludes my Tektronix 2440 Memory Oscilloscope repair. And my good friend Frans now has to buy a pair of 300MHz Probes because that is the only thing he didn’t get with this previous Defect but now magnificent instrument.

So to you all… buy or repair such a great Tektronix Oscilloscope. If I can do it so can you!

This 500MS/s 300MHz Tektronix Scope can still easily compete with todays oscilloscopes after almost 30 years !

albert1

 

Albert van Bemmelen, Weert, The Netherlands.

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17 Comments

  1. Zed Pato

    October 9, 2015 at 2:51 pm

    good job sir

    Likes(1)Dislikes(0)
  2. Albert van Bemmelen

    October 9, 2015 at 6:44 pm

    Thanks Zed, Glad you liked it.

    Likes(0)Dislikes(0)
  3. Humberto

    October 9, 2015 at 11:01 pm

    Good repair Albert. An oscilloscope is a necessary tool in our workshop.

    Likes(1)Dislikes(0)
    • Albert van Bemmelen

      October 10, 2015 at 4:38 pm

      Still my Digital meters are my most used devices of all of my test equipment. Although my meters still can't measure true RMS AC Voltages and Currents. And only sinusoidal waves are measured correct. DC measuring is never wrong. Only the LCD digital display can be to slow if any Voltage or Current would change to fast to be displayed. Which in any casy can always be easily made visible on a oscilloscope.

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  4. Anthony

    October 10, 2015 at 3:44 am

    Sensational repair Albert, Well done and congratulations to you ! Thank you for sharing the repair with us.
    Kind Regards

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    • Albert van Bemmelen

      October 11, 2015 at 5:58 pm

      Thanks Anthony! I'm very pleased with the perfect results too!

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  5. amendar

    October 10, 2015 at 6:49 am

    Hi Albert,

    Wonderful, I am glad all tests, cal., diag. passed.

    Could be any ogical reason?!

    Good luck an go on

    Likes(1)Dislikes(0)
  6. amendar

    October 10, 2015 at 11:58 am

    Wonderful,
    I am glad all tests, cal., diag. passed.
    Could be any logical reason?!
    Good luck an go on

    Likes(1)Dislikes(0)
    • Albert van Bemmelen

      October 10, 2015 at 4:24 pm

      You mean.. why the 3000 SRAM Fail disappeared out itself?
      Maybe I interrupted the Ext Diag jumper on the U664 SRAM Board briefly unintendidly while touching the components searching for hot spots. And did it change the Diagnostic Fail List.
      I'm not sure Amendar because something like that is hard to measure afterwards without doing all test over again.

      But the 6000 Fail could be triggered because of that. Sadly I didn't take pictures of the Scopescreen because the messages were dissolved before I knew it. And I don't want to open up the 2440 scope again especially while it now works like a new Fully Calibrated one. Also my own 2465A Tektronix oscilloscope has a Diagnostic test Built-in that runs automatically at every Startup at powering On. And we only need to Calibrate or repair the parts that fail in the Diagnostic Test.

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  7. Robert

    October 11, 2015 at 3:35 am

    Great article Albert. One thing though, After all that hard work I wouldn't risk putting my coffee on top of the scope!!!!
    Cheers
    Robert

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    • Albert van Bemmelen

      October 11, 2015 at 5:49 pm

      That's just what my friend Erik said! Would you believe it?

      I answered him that he shouldn't worry because I probably would know how to repair a short current problem. As you know that is what I did when I first fixed the Oscilloscope because it only blew up all Power fuses. And I drink very fast so there probably wasn't any coffee in the cup left.

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  8. Robert Calk

    October 11, 2015 at 4:42 am

    Congratulations, Albert. I'm glad that you got the scope repaired.

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  9. amendar

    October 11, 2015 at 5:18 am

    Thank you Albert,
    You explained clearly, the jumper can be reason.
    ZGood luck.

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    • Albert van Bemmelen

      October 11, 2015 at 5:53 pm

      Hope your 465 Oscilloscope is how you hoped it would be. If you already bought it of course!

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  10. Paris Azis

    October 13, 2015 at 3:10 pm

    Hey Albert

    I fully understand now, upon completion of reading this last article of yours, the reason that you forgot to shave yourself and your beard appears as noticeably grown…What an amazing “digital thirst” is the one you have man!
    Well, keep on coding, decoding, multiplexing and demultiplexing, searching for glitches in your digital signals, but remember! All of it exists only in order to represent in the highest possible accuracy the really magic world we live in. The world of the analog signals which the entire Mother Nature provides and works with…

    Thanks again for your effort.

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    • Albert van Bemmelen

      October 14, 2015 at 2:50 pm

      Thank you dear Paris. I appreciate your kind comments very much. But I probably wouldn't search as far as the Magical World you're painting. It is after all only a bit of Science without the Fiction. Maybe in the not so distant future it also will be possible to shave without having to shave yourself. Because that is a thing I do not want to waste time on since it just keeps on growing whatever I do. About this Tektronix repair I just didn't knew I was able to do an article on these quite expensive and above all Magical designed Tektronix devices until my friend brought this 2440 Oscilloscope to me for repair.

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      • Paris Azis

        October 14, 2015 at 8:59 pm

        This is what most people call “learning by doing” Albert.
        And interpreting it sequentially backwards up, “you did it, you learned it and you have written it”. Plus, you did it good!

        Greetings

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