Author Topic: [SOLVED] Rigol DG1022 attempted repair (and reverse engineering?)  (Read 5402 times)

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Offline HB9EVI

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Re: [SOLVED] Rigol DG1022 attempted repair (and reverse engineering?)
« Reply #25 on: May 20, 2021, 10:10:44 am »
a small follow up so far

I removed the supposed broken THS3095DDA; now the channel can be activated again and outputs the square wave signal again.
so no doubt that the opamp is through and also responsible for the overload protection.
 

Offline HB9EVI

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Re: [SOLVED] Rigol DG1022 attempted repair (and reverse engineering?)
« Reply #26 on: May 26, 2021, 06:26:18 pm »
problem solved!

a new THS3095DDA arrived today from Mouser; so the device is up and running again
 

Offline mojorizing

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Re: [SOLVED] Rigol DG1022 attempted repair (and reverse engineering?)
« Reply #27 on: June 02, 2021, 08:03:49 am »
This post motivated me to get out my broken DG1022. CH1 failed for some unknown reason, but it had been working when I put it away the last time I used it.  A square wave output would have a short pulse (looked like a tooth) on top of the square wave, and there was a -2vdc offset when it should have been zero.  As I trouble shot it, the CH1 DAC basically failed altogether with no output on pin’s 21 and 22. I measured the voltage outputs from CH2 pin’s 21 and 22 setup for a 1Khz, 2vP-P, no offset square wave with an O’scope .  I removed the Ch1 DAC and applied the waveforms from a Rigol DG1032 with the wavforms I measured from the working CH2.  Now CH1 had the 1Khz square wave on the front panel output but with an offset.   I installed the CH2 DAC to CH1 DAC location and still had the offset. The offset was coming from the first opamp HKJ downstream of the DAC.  I replace the DAC with a DAC904E  (https://www.mouser.com/ProductDetail/595-DAC904E) and the HKJ with an AD8009 (https://www.mouser.com/ProductDetail/584-AD8009JRTZ-R7). CH1 now works.  Funny thing, while I had both DAC’s removed I performed a self-test and the unit passed…..
Pictures are with the DAC’s removed and bad opamp circled. The shifted cap to the right was pushed aside when I hot-aired the DAC’s off the board.


 


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