Electronics > Repair
ANRITSU instrument boot up failed discuss(MS462X VNA)?
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imett:
i found iny files this patched boot disk.. sorry i don't rememberw why is patched :'(
djac:
I have now contacted anritsu. The first answer is not very hopefully:

Hello Dieter,
Thank you for contacting Anritsu EMEA region customer technical support.
Would you like us to quote for sending the MS4622B VNA CPU board to our factory in the US for repair?
This is the only option available for replacing & programming the BBRAM due to the age of the instrument (manufactured 2002).

Best regards \ Mfg
XXX

I answered:

Hallo XXX,

I suppose that the costs for a repair in US would be far to high for such an old device. But please do so.

On the other hand I can do it by myself, if I get some information:

I have disassembled the boot eprom and know the locations where it tests the BBRam for integrity. To change the code would not be complicated.
The problem is the contents of the BBRam. Best would be to get a documentation what it should contain. But it would help to get an binary image from the BBRam of a correctly running MS462x or the default image what your engineers use, if they repair the device.

What I do not understand is, why there is in the service manual no procedure given to solve this problem. The only thing that is defective is the battery, clipped on the BBRam-Chip, that costs 5$. And the battery has a life time of 10 years, means beyond the usual life time of the device.

I cannot imagine, that Anritsu expects that their customers should send their analyzer every 10 years to the us-factory only for changing a battery. The restoring of the contents is just software, that any customer can do by itself, if he gets the appropriate information and tools.

I would be not very lucky to throw away a well running analyzer only because a battery has reached the end of it's life time.

Regards Dieter Jaeger


Let's see if they are willing to give real service to it's customers.

Regards Dieter
mrf245:
Hello all, very long time no see this post.
After copied U74 file from another analyzer, the analyzer boot normally, but it lost all source CAL data, so after made this replacement, it should make source level calibration. After it be done,everything will be OK.
mrf245:

--- Quote from: imett on December 26, 2018, 08:58:51 pm ---here another info about memory mapping :-+

--- End quote ---

Hello imett,
Where did you find this mapping files? It loos like from service manual (but I have not found this in official service manual)?
mrf245:

--- Quote from: djac on December 26, 2018, 08:27:00 pm ---I have the same problem with the MS4622B. But my device was not completely dead from the beginning.

In the first step the bootloader started normally. It tried to load the application program from the floppy first, then from the internal hard disk and then successfully from NVRAM. Then he started the application program with the corresponding message.

But then nothing happened anymore. First I thought that the program image was defective and started the internal debugger of the bootloader (after power on press "1"). With the help of this debugger I was able to reload the application program from diskette into NVRAM. But there was no change.

Since the behavior corresponded exactly to what happens when you enter a non-existent Internet address as default gateway when configuring the Ethernet interface (software bug documented by Anritsu), I suspected that some bits in the BBRam, which I assume will store this configuration, might have tilted.

So I measured the voltage of the BBRam's battery without removing it from the BBRam and see, the voltage was only about 500mV.

When I then restarted the device, it remained completely inactive as in the cases described here (keyboard LEDs all on). I don't know how you can discharge a battery with a voltmeter with 10Megohm internal resistance, but obviously this was the case. The battery can't have been lifted by the probes either, because it's clipped firmly onto the ram.

If it turns out that the internet addresses are stored in the BBRam and the bits are tilted, then this would mean that the bootloader does not check the integrity of the BBRam's data via a checksum, but via a magic number. At least a program cannot read the battery voltage according to the data sheet of the BBRam.

The next question is, what is stored in the BBRam at all? Because the calibration routines mentioned in the manual, such as the user calibration, the ALC calibration and the receiver calibration, are stored in files on the internal hard disk. Only the DAC value for setting the 10MHz fundamental frequency is stored there according to the manual.

Thus, basic data seems to be stored there, such as other DAC values or also e.g. the activation of options as well as the address of the GPIB interface etc..

I suppose, therefore, that the whole device will be adjusted after a data loss as well as after production. This will probably be done by a program, which Anritsu owns for this purpose, but probably did not make available to the public.

Possibly this program is on the boot utility disk that comes with every device. Unfortunately I don't have it and I don't know any documentation about it.

Anyway, it's not enough to patch the bootloader so that it doesn't test the BBRam, although that would be very helpful, because you can run any program that the bootloader finds under A:\SYSTEM\APP.

Is there anyone here who has ever contacted Anritsu about this issue?

Greetings Dieter

--- End quote ---

Hello Dieter,
At least I know BBRAM contain ALC CAL data.
You were so lucky to find MAC error in BBRAM, to see debugger data is very good idea.

Do you know what others can debugger and monitor do (when analyzer turn on, press 1 and select 6 or 7)?

Now my analyzer has another strange problem:

After start application, it running normally,but after several minutes, it shows "vector XX, address error",or other similar errors; Measuring graphs looks like very strange; After several seconds no response at all. It should cycle power, and error comes again.

Sometimes analyzer will no report errors, just died at all.

To check this errors, we run DRAM and other RAM test (except FLASH and NVRAM test), DRAM test no response, others were OK.

We also tried replace DSP SRAM and main DRAM 16MB on board, but no work at all.

Now analyzer start app failed, stop at "starting system......"

I don't know if there is any method to monitor the background messages (maybe it can report RAM failed or other error details), it can very help for our diagnose.
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