HP 8593A dead battery, lost its' mind, now thinks it's an 8591A... - Page 1
Forum section: electronics / repair

author: darkroom
author_rank: Contributor
timestamp: August 01, 2014, 06:20:59 pm
content: Hi,I have an HP 8593A spectrum analyzer that was working just fine...but then the internal battery died. Now when I power the unit up, it thinks its' an 8591A instead of an 8593A. One thing of note, is this unit has 859XE firmware, version 930506. It was owned by a senior HP tech, who rebuilt this unit...and as I said, it was working fine before the battery died, but it may have some oddities due to the E firmware. I've verified the CPU board and counterlock are both A boards. I can't tell about the analog interface.The initial screen has the spectrum upper limit set to 1.8G, which is the upper limit of the 8591A. Running cal fails, no surprise, as the unit doesn't know what it is. Anyone have any idea how to get this unit to recognize that its' an 8593A again?Any help appreciated!Austin

author: dxl
author_rank: Regular Contributor
timestamp: August 02, 2014, 05:10:52 pm
content: Do you have a GPIB Adapter? I think "CF-2001;IDSET 8593;FLTINIT 5" could do the trick. This sets the Center frequency to -2001Hz, which enables a few extra commands. The IDSET command is probably also somewhere in the on screen display, but i only used it via GPIB once.

author: MarkL
author_rank: Unknown
timestamp: August 02, 2014, 08:51:34 pm
content: That's an odd combination you have there.If it's running 859xE firmware, you should be able to execute commands from the front panel by using "EXECUTE TITLE", as described in the 859xE Assembly-level Repair Guide (doc #08590-90316). You could also enter the passcode "-2001" by setting the CF to that value via the regular keypad.If the IDSET command doesn't work, you could ask in the... Keysight... (there, I said it) spectrum analyzer forum. There may be other commands that affect the identity; for example an 8591E is turned into a 8591C by using a form of the FACTSET command.Based on the 8591A service manual (I couldn't find the 8593A service manual), there's also correction constants stored in the battery backed RAM. If you didn't back them up, you're in for some additional calibration work beyond just the Cal output on the front.Most (maybe all?) of the 859x series have this dependency on the battery backed RAM. If you own one of these models, go backup your calibration constants! The procedure is in the Assembly-level Repair manual. It takes 10 minutes of writing down numbers on a piece of paper.

author: darkroom
author_rank: Contributor
timestamp: August 04, 2014, 06:08:16 pm
content: Hi,Thank you for the replies. I do not have GPIB, but do have RS-232.I can do EXECUTE TITLE with this firmware. I've tried FACTSET, to no avail. There doesn't seem to be any FASTSET option I've found for the 8593E (or A). I have not found any info on IDSET. What is "Keysight" (there, I said it too...)?It's a bit too late for me to backup the cal data now...if I only knew a few years ago, or if this was designed a bit differently...like using non-volatile memory, or an easily replaceable battery, that the unit let me know needed replacing. But, after I get it all back and running, I will take some screen shots of all the pertinent screens.Best Regards,Austin

author: MarkL
author_rank: Unknown
timestamp: August 04, 2014, 09:30:31 pm
content: I'm only adding to dxl's suggestion by saying you can execute arbitrary commands using EXECUTE TITLE. You don't need a GPIB or RS232 connection. Set your title to "CF-2001;IDSET 8593;FLTINIT 5;" and hit EXECUTE TITLE. Don't omit the semicolon at the end.I've never used IDSET and don't know if it will work for you. I'm mentioning FACTSET because it's also a command that can affect instrument identity and it may be important to you. You should consult the 8593A service manual for further recovery steps, or another resource is the SA forum.The 859x units that I've seen have battery stickers on the back that say when the battery was last replaced and how long it's expected to last. It's 8 years @ 25C for 859xE models; other are probably comparable.Keysight is Agilent's new name.

author: alex.forencich
author_rank: Frequent Contributor
timestamp: August 05, 2014, 06:55:35 pm
content: Interesting; I just checked the firmware ROM and IDSET does seem to be a valid command. I can see IDSET 8591, IDSET 8593, IDSET 8595, and IDSET 8596. You can set the center frequency to -2001 Hz from the front panel, then put IDSET 8593 in the title and run execute title. However, that still won't change the A to an E.

author: MarkL
author_rank: Unknown
timestamp: August 05, 2014, 10:19:32 pm
content: Maybe it will automatically detect it's an A. The OP will have to try it.Also, I noticed you have to end the title with a ";", otherwise the last command is ignored. Or, put another way, each command in the title must be terminated with a ";".Yes, I also noticed there's lots of interesting things in the ROMs! A lot of internal routines appear to be written in HP's DLP language.

author: darkroom
author_rank: Contributor
timestamp: August 06, 2014, 04:35:10 pm
content: Hi,It is now "working" again. I replaced the battery (Mouser and DigiKey have the batteries, Tidaran TL-5104). It now saves date etc. so I know the SRAM is working again. I tried the IDSET etc. commands, and now it recognized itself as an 8593A! I can see the 300MHz cal signal. I'll run CAL and see how it does... I'm not sure how much CAL is needed outside of the self calibration ability of this unit. It was passing all tests before the battery died, so unless something drifted I'm hoping nothing "internal" needs to be recal'd. Guess I'll find out.Thank you for that IDSET command. That seems to be the key to getting this unit up and running again!I can't find any info on FLTINIT. What's that for?Best Regards,Austin

author: darkroom
author_rank: Contributor
timestamp: August 06, 2014, 08:16:39 pm
content: Passes FREQ CAL, but not AMPL CAL with this error:CAL: RES BW AMPL FAILPasses CONF TEST though...Austin

author: MarkL
author_rank: Unknown
timestamp: August 07, 2014, 01:09:36 am
content: What options are installed on this unit?If you have option 001 (75 ohm), it could be a simple fix as described here:http://www.keysight.com/owc_discussions/thread.jspa?threadID=37179&tstart=0

author: darkroom
author_rank: Contributor
timestamp: August 07, 2014, 01:31:13 am
content: Unfortunately, no option 001... 50 ohm output.Thanks!Austin

author: darkroom
author_rank: Contributor
timestamp: August 07, 2014, 02:05:16 am
content: Hi Mark,But...there was a key in your referenced solution to my salvation! I loaded the default cal data, recalibrated frequency and amplitude, and it passed! So, now the only thing that is "wrong" with this unit is the comb generator doesn't output anything. I certainly could live with it as is, but I think I'll give an attempt to fixing the comb generator. I also think a GPIB board is in order.Thank you all for your help!Austin