Products > Test Equipment

Anritsu MS2721B internal CF card missing

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analogRF:

--- Quote from: brainstorm on November 05, 2021, 01:51:02 pm ---Fortunately that IC is really cheap and seems like it's obtainable :)

After running for 5min the temperature stays stable at 53C at 14V and 300mA... that's a bit more than 4W and it seems that it might be taking the power budget since all other ICs are hovering 30C :)

Thanks for the hints and experience with those things! I think test some of the pins (any recommendations on what I should see?).

I think I'll order one of those LAN91C111 anyway and replace, looks like a winner... I hopve no other passives around it are toasted and/or cause it to fail that way.

--- End quote ---

Absolutely looks like  a winner. I would definitely change it with no hesitation.That temp and power consumption is not normalfor that chip. Looks very similar to what had happened in my case to the usb controller chip. For signals i dont know, you can look the datasheet and pick some pins that you can guess what they should look like...i think cpu is trying to communicate with it and isnot getting the proper response back

fenugrec:
I'm on the edge of my seat reading this, and I don't even own one of these !

Unfortunately that SH4 cpu doesn't have the "AUD" debug interface that the older / smaller SH2 devices have, which can be used to view PC value on every branch/call - useful to find out if it's looping a small section of code...

That ASEBRK pin doesn't look like it should interfere with JTAG ? datasheet says "leave open" when not using an emu.
Were you able to look at the reset code on this thing or is it still part of that undumped flash BGA ? I quickly checked the STBCR registers and not sure if it's possible to disable the HUDI module at all, but if so : you can look at early-early boot code (I'm talking reset vector) to see if it's soft-disabled.

brainstorm:

--- Quote from: fenugrec on November 14, 2021, 05:01:05 pm ---I'm on the edge of my seat reading this, and I don't even own one of these !

Unfortunately that SH4 cpu doesn't have the "AUD" debug interface that the older / smaller SH2 devices have, which can be used to view PC value on every branch/call - useful to find out if it's looping a small section of code...

That ASEBRK pin doesn't look like it should interfere with JTAG ? datasheet says "leave open" when not using an emu.
Were you able to look at the reset code on this thing or is it still part of that undumped flash BGA ? I quickly checked the STBCR registers and not sure if it's possible to disable the HUDI module at all, but if so : you can look at early-early boot code (I'm talking reset vector) to see if it's soft-disabled.

--- End quote ---

Thanks for joining into this repair party :)

After seeing that the network IC was that hot I decided to order it and wait for it to come on the mail, which should be just a few weeks away now (just picking my battles and allocating time accordingly here :P)... I still have to poke at its signals and see if it's really misbehaving.

I'd really like to try that IC swapping first and if that fails, I'll go down the JTAG rabbit hole. @fenugrec, if you have working OpenOCD configs for that SH4 processor, hints or other suggestions I can readily use, I'd be happy to incorporate them as part of this journey.

IIRC from https://blogs.nopcode.org/brainstorm/anritsu-ms2721b-spectrum-analyzer-repair-part-2/, there was early boot(loader?) code on those binaries and check out the reset vector, so I could also see if there are further pre-Application/Usercode JTAG/debugging facilities. The debug options that are available once the user code is running are astonishingly helpful, btw, check the blogpost out... thinking out loud and getting ideas on which flanks to attach first as I go, thanks for chiming in ;)

fenugrec:

--- Quote from: brainstorm on November 15, 2021, 02:19:49 am ---After seeing that the network IC was that hot I decided to order it and wait for it to come on the mail

--- End quote ---

I think it's a good next step. Although looking at the DS, it says it can draw "up to 140mA" ? on 3.3V right ? that's a fair amount of power, probably only in certain cases, but if the CPU is leaving that IC in a weird state (or spamming some function inside it that draws more power) it could be another wild goose.
How about removing it altogether in the meantime ? See if that affects the boot sequence at all ?



--- Quote ---if you have working OpenOCD configs for that SH4 processor
--- End quote ---
Sorry, haven't much to add. HUDI/JTAG wasn't easily accessible on the board I worked on but AUD was, and that provided what I needed.

JTAG should give you at least boundary scan according to the DS... Is it realistic to write some massive bitbanging code to read the external memory that way ?
Otherwise I'm not sure what else it provides if there's no support code in the fw...


--- Quote --- The debug options that are available once the user code is running are astonishingly helpful
--- End quote ---

Oh do you still have access to the vxworks console ?
IIRC you can even load + run arbitrary code that way, right ?

brainstorm:
Hi folks, I've started a new thread on this over:

https://www.eevblog.com/forum/repair/anritsu-ms2721b-component-level-repair/new/#new

Since I think that the topic does not reflect what's going on with my instrument anymore, I hope you don't mind? ;)

@analogRF and @fenugrec, please subscribe over there for further updates ;)

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