ADP3450 Analog Channels non-functioning

[Kurt Henry]

 Good day. I have purchased 2 ADP3450s 13 and 12 months ago. The first one is now faulty where the scope / analog channels are now clamped. The waveform generator and digital are OK. Firstly what can be done to repair this device as it is a staple for my work? Secondly is this an ongoing issue with the product line? Do I need to repair / return the 2nd? I wanted to purchase an additional one for my team and has any update to design or QC been made  since last purchase (May 2021)?

[JColvin]

Hi @Kurt Henry,

I have moved your question to a more appropriate section of the Forum where the engineer most familiar with the ADP3450 hardware will be able to see and respond to your question.

Thanks,
JColvin

[Jim_G]

I'm also interested in your responses as I have a similar symptom. In my case I have a Analog Discovery II where I have over-voltaged one channel (Ch2). Open circuit, channel 1 correctly reads milliVolts, channel 2 reads -29.799 Volts. Looking for repair guidance - I'm comfortable doing hot-air SMT rework.

Thanks,

Jim

[attila]

Hi @Jim_G

You should have gotten response to your support email in ADP3450 topic.
We suppose you've tried to cycle the board power.
You could try to load the factory calibration or reset to zero under WaveForms/Device manager/Calibrate/Reset. The values should be small like in the picture.
You could also try the latest version from here: https://forum.digilent.com/topic/8908-waveforms-beta-download/ 
and starting it in WaveForms in Safe Mode, to prevent loading of application/device options, recent files...
If these don't help the oscilloscope ADC driver, offset or reference circuit is probably damaged.

Do you know what was the last experiment the device was used? Could you describe the setup, tested component/circuit ?

I don't remember seeing such failure with ADP3X50 but high voltages could damage the device like I've heard AD2's damaged by piezo electric experiment with 100s-1000s V

On ADP3X50 each scope input has a ADA4817-2ACPZ next to the upper relays IC3,9,15,31
This is the first IC in the input path so probably these are damaged.

On AD2 probably the ADG612 is damaged, see:

For other problems see:

 

[Kurt Henry]

Hi attila,

All my work is on IC's and voltages supplies below 5.5v. Worst case I can think of is a ground path via the analog channel for 7-8mA tops. Would all 4 op amps fail simultaneously? Why are 3 channels negative and 1 positive? If you provide schematics I can test individual IC's to help diagnose.

Thanks,

Kurt

[attila]

Hi @Kurt Henry

Did the device and your circuit have a common ground ?
Without proper grounding there could be high voltage differences that could damage the device/circuits.

According the discussion with the team, it would be complicated to troubleshoot, so please go for replacement.

Edited May 27, 2022 by attila

[Jim_G]

Hi. One of my AD2 channels was 'stuck' at -29.799. It turns out that one of my ADA4051-2ARMZ opamps was damaged, and was putting 5.5V out to the VREF_SC2 pin. I had been trying to measure output impedance of a high-power amplifier through a cap-coupled connection. The amp went unstable with several hundred volts ptp. So I'm not surprised something broke, but I was expecting the front-end device to be damaged, not an amp further inboard.

Anyway, it is working well now after the repair. Just documenting this in case I do it again or if it will help anyone else.

Thanks, Jim 

[attila]

Hi @Jim_G

I'm glad to hear it is working again and thank you for the information.