Agilent/Keysight N1911A Powermeter - Number of measurement boards wrong - Page 1
Forum section: electronics / repair

author: mischo22
author_rank: Contributor
timestamp: November 28, 2024, 04:05:51 pm
content: Hello.I have an Agilent N1911A power meter here. I used it and put it in the cabinet. After 2 months I wanted to use it again. When I switched it on, it started in an emergency bootloader. I suspected that the software on the flash was defective. The screen message said that I should reinstall the software.I then tried to update the latest firmware. When I updated, I received a message that the DAP2 DSP and FPGA component could not be updated. After the restart, the software was there again, but shows the message "Can't find the required number of measurement boards".Is it possible that the flash has lost the data? My guess: the device now thinks it is an N1912A, so it has two channels, and therefore two DSP boards.I have already contacted Keysight. They only have a flat rate for repairs for this type of device, which is so high that it exceeds the price I paid for the device used at the time.Any ideas what I can do?

author: Harry_22
author_rank: Frequent Contributor
timestamp: November 29, 2024, 10:27:34 pm
content: Hi!It seems all is not lost yet.The following note is written in service manual: Fitting a PPMC assembly that has been pre-programmed with N1912A firmware to anN1911A power meter will generate errors; these errors will disappear once the firmware upgrade procedure has been carried out.Is it still possible to re-run the upgrade procedure?Logically, the model should be specified in the device Setup.Check the internal battery.https://drive.google.com/file/d/1OuvcG0lGVkYRMqqmjmmprsuS0B9R4L28/view?usp=sharing

author: mischo22
author_rank: Contributor
timestamp: November 30, 2024, 08:05:18 pm
content: Hi Harry_22!You mean I should start the firmware update again?I've already tried that several times. Unfortunately, the firmware updater also recognizes the device as N1912A and tries to update the DSP of the 2nd channel, which always fails.On the device's website, the device type is also shown as N1912A.The battery is OK. It has 3.1V

author: Harry_22
author_rank: Frequent Contributor
timestamp: December 09, 2024, 01:36:14 am
content: Quote from: mischo22 on November 30, 2024, 08:05:18 pmSorry for delay. Could you check the device type that is currently shown in setup menu.

author: mischo22
author_rank: Contributor
timestamp: December 09, 2024, 01:00:29 pm
content: I did a little more research and was able to solve the problem:The firmware update consists of two different software versions. One for the N1911A (one channel) and one for the N1912A (two channel).The updater uses the SCPI command *IDN? to recognize the device type and updates the device with the appropriate firmware.The emergency bootloader always reports N1912A. Therefore, the two-channel version would be loaded during the update.I have now swapped the type strings in the FwUpdate.exe file, i.e. changed N1911 to N1912 and vice versa with an editor.After the firmware update, the correct version was loaded and the device is working properly again.I think there would be an easier way, such as undocumented command line parameters for the updater, but my version works perfectly.