Have your tried just updating the OS with a blank CF card installed? The updater on later models, at least, will load before the instrument fully boots if the USB stick is in at power on. There's also an alternate firmware loading mode (not sure if it normally resides on the flash, though) that's accessible from startup with a button sequence, though again I don't know whether this applies to B models.
In any case, it could be worth contacting Anritsu support. They've been helpful to me a couple of times (replacing a tilting bail and downgrading a firmware update that caused issues), so while they may just say "send it in for service" they also may be able to help you out.
I own a MS22723B which I purchased a couple of years ago and was going to do a tear down and review but forgot to. I ended up taking it apart to replace the screen protector as the original was scratched and yellow I have attached photos. Maybe somebody can compare lower spec models with mine to see if there are any hardware differences. AnalogRF I don't understand why Anritsu informed you that the main PCB needs changing as the service manual lists the 512MB internal flash card as a replaceable part (3-2000-1567). If it helps I'm willing to take apart my unit again and have a look what's on my flash card maybe there are files on there with model and serial numbers which are scanned during boot up I don't know I always thought the card was for storing calibration data any way let me know if I can help.
Here's a followup on my repair efforts if somebody is interested:
https://blogs.nopcode.org/brainstorm/anritsu-ms2721b-spectrum-analyzer-repair-part-2/
... r2/ghidra give quite a bit of insight on how to repair the boot process on my instrument (i.e when the CF card is "not good"), hope it helps someone else in my situation!
I purchased the same unit over ebay a while ago and also had the internal CF missing (with slightly broken holder as if it was removed by force). I wrote up my experience trying to boot it up with a firmware update image (with limited yet encouraging success) over here:
https://blogs.nopcode.org/brainstorm/anritsu-ms2721b-spectrum-analyzer/
TL;DR: I managed to dump the uncompressed memory contents to poke around with a few of the VxWorks functions to diagnose the underlying problem(s).
I think it would be of very high value (to me, perhaps others), if some of you owning the instrument could:
1. Connect it via ethernet to your home router or equivalent and power it up.
2. Telnet into it via the DHCP-assigned IP address.
3. Run a few of the commands outlined in the blogpost and paste the output back over here.
I'm specially interested on the VxWorks shell commands: DoRAMTest, sysSelfTest, sysOptionUpgrade and dumpEEPROM... to start with
You can either run the python script published on my blog to retrieve a ton of callable-from-the-VxWorks-shell functions and offsets or ask me about the .csv if you are interested.
/cc @Thedon, from your photos, you seem to have a fancy version of the unit with GPSDO and extra RAM daughter board? Interesting!
Cheers!
Here's a followup on my repair efforts if somebody is interested:
https://www.reddit.com/r/ReverseEngineering/comments/g0g8w2/vxhuntervxworksradare2_a_spectrum_analyzer_repair/
... r2/ghidra give quite a bit of insight on how to repair the boot process on my instrument (i.e when the CF card is "not good"), hope it helps someone else in my situation!
Awesome news, I'm so happy for you @AnalogRF!
My instrument needs review on the power rails/capacitors, it was a bit finicky on power-on before and now it doesn't even turn on, just flickers. I tried the MST software before but couldn't get a connection so no firmware update was possible, I'll take your advice into account when the hardware side is back in good health
So unfortunately I cannot dump the EEPROM... yet. If you are based in Melbourne we can meet and exchange notes perhaps? Happy to!
You must have the 12.2V (I think at two of them IIRC), 1.8V,3.3V, 5V, 4V
Hello @AnalogRF,
I now have a proper lab PSU that can do up to 30V and 6A (ITECH triple output IT6302)... it is definitely a big improvement over the dodgy chinese wall wart I had before XD
I have been chasing the voltage rails you mentioned under the Anritsu tin can:QuoteYou must have the 12.2V (I think at two of them IIRC), 1.8V,3.3V, 5V, 4V
I have attached a few of them in this post, it would help a lot if you could verify that those are the same you are seeing on your board. I'm powering the main board with 15V and it barely consumes 350mA, no chip gets hot AFAICT and I've disconnected *everything* (no screen attached, no cold tube board, no CF card, etc...). Please let me know if there's any critical rail that I should specifically check, I have "The Signal Path" youtube video screenshot as a reference, but since that video is from the "A" model (attached below, image with red post-it stickers), there are a few differences.
There's a very small "PWR_FAIL" via that reads 3.3V... but since it's close to the battery charging circuit, I doubt it's an "overall" diagnostic for the instrument's power supply, but just a battery present/not present type of check?
@AnalogRF, I could not locate the 12.2V rail you suggested. The closest seems to be the input voltage (using 15V input via the barrel jack, with 0.2V voltage drop for the cable leads).
As I mentioned a while ago, the processor seems to be alive (3.3V and RDY/RESET signals) and the screen does flicker on boot, but doesn't get very far. When I connect the screen, it oscillates very slowly between 300 and 400mA, which suggests a bootloop.
I'll be taking a closer look at the RAM chips soon since I have some suspicion that one of them is not behaving exactly as the other does, but if anybody has other good troubleshooting suggestions, I'm all ears
Hello @AnalogRF,
I now have a proper lab PSU that can do up to 30V and 6A (ITECH triple output IT6302)... it is definitely a big improvement over the dodgy chinese wall wart I had before XD
I have been chasing the voltage rails you mentioned under the Anritsu tin can:QuoteYou must have the 12.2V (I think at two of them IIRC), 1.8V,3.3V, 5V, 4V
I have attached a few of them in this post, it would help a lot if you could verify that those are the same you are seeing on your board. I'm powering the main board with 15V and it barely consumes 350mA, no chip gets hot AFAICT and I've disconnected *everything* (no screen attached, no cold tube board, no CF card, etc...). Please let me know if there's any critical rail that I should specifically check, I have "The Signal Path" youtube video screenshot as a reference, but since that video is from the "A" model (attached below, image with red post-it stickers), there are a few differences.
There's a very small "PWR_FAIL" via that reads 3.3V... but since it's close to the battery charging circuit, I doubt it's an "overall" diagnostic for the instrument's power supply, but just a battery present/not present type of check?
@AnalogRF, I could not locate the 12.2V rail you suggested. The closest seems to be the input voltage (using 15V input via the barrel jack, with 0.2V voltage drop for the cable leads).
As I mentioned a while ago, the processor seems to be alive (3.3V and RDY/RESET signals) and the screen does flicker on boot, but doesn't get very far. When I connect the screen, it oscillates very slowly between 300 and 400mA, which suggests a bootloop.
I'll be taking a closer look at the RAM chips soon since I have some suspicion that one of them is not behaving exactly as the other does, but if anybody has other good troubleshooting suggestions, I'm all ears