PXI-4472 Problem: Several channels always oscillating between +/- 10 V

[chc5e]

Hello,
Hoping that someone has seen a similar problem. This just recently came up. Observable when running LabView VI's as well as in MAX test panels.

Any ideas on the cause? Any ideas on the fix?
Would appreciate your help,
Hunter

[Shea C]

Hunter,


Are you seeing this oscillation on top of existing signals that you are trying to acquire? Are the channels that you are seeing the oscillation on connected to anything? What type of signal are you expecting on the channels that you are reading from? What types of sensors are you interfacing with? Is this oscillation seen in MAX? Can you give more details to the system?

Regards,

Shea C
Applications
NI

[chc5e]

Hello, Shea
To answer your questions:
Yes, we see this on top as well as when no signals are connected.
We are looking at voltages from eddy current prox probes in the 0 to -5 V range, using DC coupling.
Yes, as I stated earlier, this oscillation are seen both in LabView and in MAX.
This board is mounted in a PXI-1002 chassis. The chassis incorporates a MXI-3 board and three 4472 boards.
This problem board is located in the master slot beside the MXI-3. The other two 4472 boards seem to be operating fine.

Look forward to hearing your thoughts ASAP.
Thanks,
Hunter

[Shea C]

Hunter,

That behavior seems to indicate there could be something wrong with the board itself. I would suggest swapping connections of the board in question with another board assumed to be operating correctly. If the problem seems to stay with the board in question, I would recommend contacting NI Support at 1-866-275-6964 to troubleshoot with an Applications Engineer. If it is determined that the board needs repaired having the serial number available will speed up the process.

Shea C
Applications
NI

[chc5e]

Hi, folks

To follow up on this problem, I sent the board back to NI. According to report, they found "Power supply not working, multiple shorts in channels". Basically the board is unrepairable. I haven't been given a possible cause, yet.

All the best,
Hunter