Author Topic: Tektronix AWG2020 Restoration  (Read 3098 times)

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Offline danpoarch

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Tektronix AWG2020 Restoration
« on: March 19, 2015, 04:12:40 pm »
I plan on posting a much longer piece on the cleaning and restoration of this waveform generator, but I have a quick question about cleaning the analog output boards.

There's a lot of components on these boards that I either haven't worked with before, or haven't had to deal with as part of a cleaning. I just want to know if someone sees anything here that I should watch out for. The generator works, but has some output scaling issues and gives off failure codes for these particular boards. My aim is to improve its performance, not degrade it. ; )

My typical process:
- Soak with foaming Simple Green Crystal
- Rinse with distilled water (would use DI if I was rich or had a place I could steal it from)
- Spot clean with 99.9% isopropyl while removing the old capacitors
- Spot clean again
- Use Caig DeOxit on the corroded legs of the regulators and xstrs.
- Rinse-repeat, if necessary

This method works beautifully on the beige Macs I restore, and served me well on the other boards on this unit.

The data sheet for the Omron G6H-2 relays says, "When washing the product after soldering the Relay to a PCB, use a water-based solvent or alcohol-based solvent, and keep the solvent temperature to less than 40°C. Do not put the Relay in a cold cleaning bath immediately after soldering." I won't be reworking those, but they look safe to get wet as part of the cleaning process.

I really like this generator and for $300 and a lot, but not unreasonable amount, of elbow grease it has excellent value. The frequencies seem to be dead on (at least at 4.5 digits, which is all I need) and I like having two channels, not to mention the arbitrary waveform features. Like I said, my hope is help, not harm it.

« Last Edit: March 19, 2015, 04:39:48 pm by danpoarch »
 

Offline danpoarch

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Re: Tektronix AWG2020 Restoration
« Reply #1 on: March 19, 2015, 04:26:11 pm »
Sorry if I wasn't clear, I'm tearing into these boards and completely replacing the aluminum SMT caps with Nichicon solid polymer CVs. And trying to clean and prevent further damage from the leaking old ones as I go.

Caps:
http://www.mouser.com/Search/ProductDetail.aspx?R=PCV1V220MCL2GSvirtualkey64700000virtualkey647-PCV1V220MCL2GS
http://nichicon-us.com/english/products/pdfs/e-cv.pdf
 

Offline meriororen

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Re: Tektronix AWG2020 Restoration
« Reply #2 on: April 27, 2017, 07:00:01 pm »
Hi,

I know this is an old topic.
I also recently have just got an AWG2020, all working except it fails at Setup CH1 (642) , apparently analog board fault.
Also, sometimes the Clock too has 212 fault, synthesizer board fault. However when I run calib, it passes, run again and it failed.

I opened the case only to find all those leaky caps has been replaced with new throughhole electrolytic caps with either 22uF 50v value
or 33uF 50v value.

 

Offline danpoarch

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Re: Tektronix AWG2020 Restoration
« Reply #3 on: April 28, 2017, 12:03:31 am »
Yikes. That probably means that the boards that the boards were never cleaned. I would think about washing them in Simple Green, or similar, ASAP.

I also discovered two more caps buried in soldered-down RF cages on the board that seems to handle timing/triggering (been a while since I've worked on this project so I think that's what the board does). Haven't quite figured out how I'll get to those to replace them.

If our Signal generators can last thirty years, this thread can last just as long... ; )
 

Offline meriororen

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Re: Tektronix AWG2020 Restoration
« Reply #4 on: April 28, 2017, 12:47:51 pm »
Despite of these faults, actually it can still output waveform. I wonder what effect does these faults cause.

Also, Is this thing can only generate 2.5 MHz? I can't seem to go higher than that frequency in F.G. menu.
 

Offline TAMHAN

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Re: Tektronix AWG2020 Restoration
« Reply #5 on: April 29, 2017, 07:21:03 pm »
Hello,
just checked on my AWG2021, same "problem" re the 2.5MhZ!

You are dealing with two units tacked together here: a "function generator" in the FG menu, and a seperate arb. They are different in quite a few aspects, notably that the Arb expects 50 Ohm termination while the FG can also do high impendance loads (to some extent).

Tam
Feel like some additional tamile wisdom? Visit my YouTube channel -> https://www.youtube.com/user/MrTamhan for 10min tid-bits!
 

Offline meriororen

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Re: Tektronix AWG2020 Restoration
« Reply #6 on: April 30, 2017, 12:09:36 am »
I actually "figured" it out without reading manual.  :-+

You need to make a waveform, and then "play" it. To make a waveform, use EDIT menu, save it into a file in either diskette or nvram,
then "play" it on SETUP menu.

Here's one in action outputting 30MHz, it's upside down because I am probing the analog board which is located at the bottom. The pic's rather blurry though.

 

Offline TAMHAN

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Re: Tektronix AWG2020 Restoration
« Reply #7 on: May 03, 2017, 09:48:42 am »
Please test square waveforms or ramps, so we can easily see memory related problems.

Feel like some additional tamile wisdom? Visit my YouTube channel -> https://www.youtube.com/user/MrTamhan for 10min tid-bits!
 

Offline meriororen

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Re: Tektronix AWG2020 Restoration
« Reply #8 on: May 04, 2017, 01:31:02 pm »


This is as fast as I can get (right now as I have yet to figure out more of its setup) with 250MHz clock using square wave. 250 cycles of square waves resulting 62.5 MHz. If I go further than 251 cycles I start seeing discontinued waveform.

Will keep posted.


Sent from my iPhone using Tapatalk
 

Offline TAMHAN

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Re: Tektronix AWG2020 Restoration
« Reply #9 on: May 05, 2017, 12:02:14 am »
Merio, we want the LONGEST POSSIBLE waveform as to exercise ALL memory cells.

Speed, for now, is not so important.
Feel like some additional tamile wisdom? Visit my YouTube channel -> https://www.youtube.com/user/MrTamhan for 10min tid-bits!
 

Offline TheNewLab

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Re: Tektronix AWG2020 Restoration
« Reply #10 on: July 06, 2018, 04:07:50 pm »
Excellent! I am staying on this thread to keep it alive. I would love to hear anymore of your progress. i recently got two AWG2021. It says up to 250MHz. I am not sure how to do it. So far I think it is about turning up the internal clock and I have to create my own custom AWG..and somehow push enough into the file I created to get the 250MHz.

 


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