Tektronix AWG 2020 / 2021 schematics

Discussion in 'General Electronics Chat' started by Nibbler, Oct 22, 2013.

  1. Nibbler

    Thread Starter New Member

    Jan 27, 2013
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    My AWG2020 won't start up. I found some leaky caps but need schematics to complete repair because of electrolyte corrosion.

    Are the schematics still available? Anyone know where?

    Service manual doesn't have them...

    Thanks
     
  2. DerStrom8

    Well-Known Member

    Feb 20, 2011
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  3. Nibbler

    Thread Starter New Member

    Jan 27, 2013
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    Thank you for that. Unfortunately, yes it doesn't have schematics.

    I need to verify some damaged traces from the cap leakage, and the only way to do it is with schematics... Or some hi-res photos of the "A6 CPU Board" front and back.

    It is interesting that the AWG 2005 and 2020 and 2021 are very related. I don't know the exact differences but they all appear to have the same layout and internal board designators.

    Schematics for any of the series would be helpful to me if anyone has them or knows where to find them.
     
  4. Nibbler

    Thread Starter New Member

    Jan 27, 2013
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    Problem solved.

    The A6 (CPU), A10 (synthesizer), A21 (channel 1), and A31 (channel 2) boards had bad caps. A total of 12 were changed out. And 8 PCB traces repaired from electrolyte corrosion.

    End results, AWG2020 passes self tests, calibrates, and functions correctly.

    If you get the "Illegal Configuration" type of error, it means that the A21 and A10 boards likely have bad capacitors also.

    Caps were all SMD 22uf@35V EMVY350ADA220MF55G
     
  5. DerStrom8

    Well-Known Member

    Feb 20, 2011
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    I can honestly say I don't think I've ever heard of SMD caps going bad. Make sure there's not something else that caused them to fail, otherwise you'll have to do this all over again at some point in the future :p
     
  6. Nibbler

    Thread Starter New Member

    Jan 27, 2013
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    I'm talking about SMD electrolytic capacitors. They fail all the time in older electronics. They vent their electrolyte and it causes corrosion.

    I've seen it commonly in older computers.
     
  7. DerStrom8

    Well-Known Member

    Feb 20, 2011
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    Woops, was thinking of the flat chip capacitors. SMD Electrolytics makes a lot more sense :p
     
  8. Nibbler

    Thread Starter New Member

    Jan 27, 2013
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    I agree with you, those types of caps fail because of other problems. But electrolytics are a mess after 15-20 years or so.
     
  9. DerStrom8

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    Feb 20, 2011
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    That's actually being very generous. I tend to have problems with them after only 5-10 years :eek:

    Anyway, I'm glad to hear you got it fixed! Did you just guess on where the traces were supposed to go, or did you find documentation? I recently repaired a HP1741A Scope that stopped working because a through-hole electrolytic exploded and corroded the traces. I had to follow the traces to figure out where they were supposed to go before repairing them.

    Matt
     
  10. Nibbler

    Thread Starter New Member

    Jan 27, 2013
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    No documentation. Just a powerful magnifier, continuity checks to find the bad traces, and time... Lots of time.
     
  11. DerStrom8

    Well-Known Member

    Feb 20, 2011
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    Well nicely done! It's always a great feeling when you're able to repair something like that.

    Keep up the good work!
    Matt
     
  12. Nibbler

    Thread Starter New Member

    Jan 27, 2013
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    Thanks! Yes, getting through the first error message was quite a relief (especially since it was not a documented error type). I enjoyed the process of reviving it.

    It's a shame more of this type of gear don't have schematics available...
     
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