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2465B .. test 04 fail 01 ... what's?

Joseph
 

In the service manual I found this :

[img]https://image.noelshack.com/fichiers/2020/03/1/1578874941-capture-2020-01-13-a-01-20-24.jpg[/img]

What does that mean"parity error on read"?
What is the action to resolve this problem ?

satbeginner
 

To me it seems the data in the Dallas memory has gone wrong...

Action: 1. replace Dallas (buy a proper one at eg. Mouser )
2. Calibrate the scope

Let others add experiences as well

Chuck Harris
 

The simple answer is it means that your calibration
data is lost.

The cause is usually a dead battery... either in a NVRAM part,
or a separate lithium cell... depending on the serial number of
your scope (B050000 and greater: NVRAM, B049999 and lesser:
separate battery)

The location of the NVRAM, or battery, is on the A5 controller
card on the right side of your scope.

The solution is to replace the NVRAM, or battery, and have your
scope recalibrated.

Do not buy a preprogrammed NVRAM. It will not allow your scope
to function accurately. Each scope has its own unique calibration
data, that can only be discovered through calibration.

-Chuck Harris

Joseph wrote:

In the service manual I found this :

[img]https://image.noelshack.com/fichiers/2020/03/1/1578874941-capture-2020-01-13-a-01-20-24.jpg[/img]

What does that mean"parity error on read"?
What is the action to resolve this problem ?



Joseph
 

Strange because I see the NVRAM datas on my programmer
Is it possible that the problem could come from a break track? ... I unsoldered with difficulty the NVRAM ?

 

That does not mean the data you see is correct.  The 2465x oscilloscopes check memory integrity on power up.  One of those checks is a checksum calculation that tests every bit in the active range of the memory against a known value also stored in the same memory.  Nearly any case of a bit in error will produce that error message on power up and/or system test.  The only reasonable fix is to restore all the data which requires a calibration.  As it stands, you can read whats there and so can the scope computer, but the scope computer doesn't like what it sees, whether it looks right to us or not.

On Monday, January 13, 2020, 11:29:55 AM CST, Joseph <@jo6466> wrote:

Strange because I see the NVRAM datas on my programmer
Is it possible that the problem could come from a break track? ... I unsoldered with difficulty the NVRAM ?

Chuck Harris
 

You will see data, but it won't likely be valid data.

Look for the date code on your NVRAM. It is most likely
from 1990, or so.

The NVRAM was specified to have a minimum 10 year data
retention life... I am sure yours is way beyond that.

What's the maximum? It depends on how it lived its
life: hot, cold, turned on, turned off, good luck, bad
luck, ...

Also, the pin soldering spec is 260C(500F) max for 10 secs
max.

Very few folks use 500F soldering iron tips... 700F is
the general purpose tip that comes with most soldering
stations.

If you used solderwick, a cheap rubber bulb type desoldering
iron, or a spring loaded solder sucker, it is almost
guaranteed that you overheated some of the internal solder
joints in the NVRAM. Does it matter? Depends on how
lucky you are.

-Chuck Harris



Joseph wrote:

Strange because I see the NVRAM datas on my programmer
Is it possible that the problem could come from a break track? ... I unsoldered with difficulty the NVRAM ?