Agilent E4404B Spektrum Analyzer display has lines on it and no frontpanel acess - Page 1
Forum section: electronics / repair

author: Arthur_Dent129
author_rank: Newbie
timestamp: January 23, 2022, 10:27:06 am
content: Hello Community,my E4404 Speci doenst't work anymore properly he has a big fat line on the display, also no picture via external VGA monitor and ecternal Keyboard.I guess the processor board is broken or ?I have an N 8974A Noise Figure Analyzer with RF problems but the Processor board is fine, it is possible to use it to repair my E4404 ?Maybe change the EE-Prom and flash other firmware on it ?Maybe someone has useful tips and tricks for me to do it.Thx and RegardsArthur

author: SoundTech-LG
author_rank: Frequent Contributor
timestamp: January 23, 2022, 02:29:02 pm
content: Can you at least check the power supply lines?

author: Arthur_Dent129
author_rank: Newbie
timestamp: January 23, 2022, 09:34:37 pm
content: Hi,I measured at the front where the the probe power is normally located (the three pin connector) or ?On the Left Pin to GND = + 15V DC and on the right Pin to GND -12 V DC it seems to me ok concerning Service Manual or ?Also the Fan is running that means the -7 to -12.2 Volt is alos ok or ?Where can I mwasure the +5 V and the - 5V for this case I must remove the power supply or is a test Pin also somewhere installed on some PCBs ?On the Processor Board is a Green LED blinking.See attached pictures with the faulty screen.Thx and Regards

author: SoundTech-LG
author_rank: Frequent Contributor
timestamp: January 24, 2022, 03:27:01 pm
content: get this first:https://www.keysight.com/us/en/assets/9018-04013/service-manuals/9018-04013.pdf?success=truethen:Chapter 1 25Troubleshooting the AnalyzerTroubleshooting the LCD DisplayTroubleshooting the LCD DisplayThe only adjustment that can be made to the LCD display is the viewing angle.This is found on the front panel of the analyzer in the upper left corner.Viewing Angle1. Verify that the analyzer has gone through a full power-on sequence. Refer tothe section “Troubleshooting an Inoperative Analyzer” on page 21.2. If the display is dark (not visible), connect an external VGA monitor to the rearpanel VGA output connector on the analyzer. It is possible that some multisyncmonitors may not be able to lock to a 60 Hz sync pulse. If the videoinformation is not present on the external VGA monitor, the most probablecause is the A4 processor assembly.Then, use this section to TS the Processor...Troubleshooting the A4 Processor AssemblyAfter you have determined that the problem is caused by the A4 processorassembly, use the following procedures to determine if A4 must be replaced or if itcan be restored to normal operation. The ESA Spectrum Analyzer & EMC AnalyzerComponent-Level Information is required to assist with some of these procedures.Refer to Chapter 5 for a list of available component-level service information.

author: Arthur_Dent129
author_rank: Newbie
timestamp: January 29, 2022, 07:45:23 pm
content: Hello short Update,I change the processor A5 Board from a broken N893 Noise figure Anaylzer and the E4404 Display and Fronpanel works again, so it seems I am on the right track to fix it.I am not sure If the 12 MB flash SIM is working correct or broken too,it will only boot with the 4 MB flash SIM of the NFA instead.On the Keysight spare parts store I found that is not orderable.I found that the part NUmber is E4401-60081,but google doesn't give me a hint where I can find an alternative flash Sim to replace.Maybe somewhere in the community has a link ?My nextsteps are looking for the flash sim and them flash the firmware from the Website via floppy disk and then it hoepfully works.I guess with not ennough RAM (4MB) and flash Sim (4MB only the very old firm ware will work of is that not correct ?RegardsArthur