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11A-series plug-in NVRAM replacement: Difference between revisions

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11A-series plug-in NVRAM replacement (view source)

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The following detailed explanation of how to replace the NVRAM of an [[11A16]], [[11A32]], [[11A33]], [[11A34]], [[11A52]], [[11A72]] plugin is courtesy of [[John Addis]].
The following detailed explanation of how to replace the NVRAM of an
[[11A16]], [[11A32]], [[11A33]], [[11A34]], [[11A52]], [[11A72]] plugin is courtesy of [[John Addis]].



Some portions of John’s procedure do not appear in any Tek manual which makes it impossible to permanently recalibrate the plugin after the NVRAM has been replaced without the information John compiled into this procedure.



Some portions of John’s procedure do not appear in any Tek manual
which makes it impossible to permanently recalibrate the plugin after the NVRAM has been replaced
without the information John compiled into this procedure.




An expired battery inside the NVRAM in 11A16, 11A32, 11A33, 11A34, 11A52, 11A72 plugins results in three problems:


An expired battery inside the NVRAM in 11A16, 11A32, 11A33, 11A34, 11A52, 11A72 plugins results in three problems:


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3. Failure to retain V/Div, Offset, Probe calibration, etc. after turn off.
3. Failure to retain V/Div, Offset, Probe calibration, etc. after turn off.


There may be other failures directly caused by the NVRAM, so multiple failures should not discourage you.
There may be other failures directly caused by the NVRAM,
so multiple failures should not discourage you.


Note: the 11A52 is a special case in that the high frequency response (a single pot pre channel in the 11A32 and 11A34)
Note: the 11A52 is a special case in that the high frequency response
(a single pot pre channel in the 11A32 and 11A34)
is instead encoded in 12 calibration constants (six per channel).
is instead encoded in 12 calibration constants (six per channel).
These are lost in the 11A52 along with the serial number, instrument settings, and probe settings at last turn off.
These are lost in the 11A52 along with the serial number, instrument settings, and probe settings at last turn off.
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I have successfully programmed the serial number into my 11A32 using an NVRAM purchased for $7.50 from China.


I have successfully programmed the serial number into my 11A32 using an NVRAM purchased for $7.50 from China.
Reprogramming the serial number is necessary to prevent the plugin from going through a calibration cycle at every turn on.
Reprogramming the serial number is necessary to prevent the plugin from going through a calibration cycle at every turn on.
Any legitimate serial number will work, but I suggest you program the serial number printed on the top rail of the plugin. That is what Tektronix did.


Any legitimate serial number will work,
but I suggest you program the serial number printed on the top rail of the plugin. That is what Tektronix did.




The plugin service manual tells you how to reprogram the serial number, BUT THAT DOES NOT WORK BECAUSE IT IS INCOMPLETE.


The plugin service manual tells you how to reprogram the serial number, BUT THAT DOES NOT WORK BECAUSE IT IS INCOMPLETE.


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Here is what you do:

  
Here is what you do:

  


Remove the bottom panel of the mainframe. On the board closest to the front panel (Time Base board), locate J450 labeled “CAL-LOCK”.
Remove the bottom panel of the mainframe.
This is hard to find. It is near the center of the board, about 1” toward the rear of center and 1.5” away from the CRT side. See Fig 3-15 if you have a manual.
On the board closest to the front panel (Time Base board), locate J450 labeled “CAL-LOCK”.
Short these two pins together with a jumper of some sort. J450 is probably the name on all 11K mainframes.
This is hard to find.
It is near the center of the board, about 1” toward the rear of center and 1.5” away from the CRT side. See Fig 3-15 if you have a manual.
Short these two pins together with a jumper of some sort.
J450 is probably the name on all 11K mainframes.




In the plugin, remove the left side panel, remove and rotate the J611 jumper on the plugin


In the plugin, remove the left side panel, remove and rotate the J611 jumper on the plugin
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(Utilities button > Page to Utility 2 Menu > RS-232-C).
(Utilities button > Page to Utility 2 Menu > RS-232-C).
HyperTerm is not free on Windows versions after XP but any serial communications program will work.
HyperTerm is not free on Windows versions after XP but any serial communications program will work.
See [http://helpdeskgeek.com/windows-7/windows-7-hyperterminal http://helpdeskgeek.com/windows-7/windows-7-hyperterminal] for some alternative suggestions.


See [http://helpdeskgeek.com/windows-7/windows-7-hyperterminal http://helpdeskgeek.com/windows-7/windows-7-hyperterminal]
for some alternative suggestions.




You can check that this is working by typing in any legitimate (probably case sensitive) command:  
You can check that this is working by typing in any legitimate (probably case sensitive) command:  
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CHR2 BW:1E6
CHR2 BW:1E6
</pre>
</pre>
CH means CHannel.  The letter following CH specifies the plugin hole you are using L, C, or R.  LEF, RIG, and CEN are also acceptable. The number following L, C, or R is the channel number.  Once this is all working (answering in English), type in the following command to program the serial number:

UID CENTER:″B010200″ where you substitute the serial number on the top rail of your plugin for B010200 and LEFT or RIGHT for CENTER as appropriate. No space between the colon and the  double quotation mark.


CH means CHannel.
The letter following CH specifies the plugin hole you are using L, C, or R.  LEF, RIG, and CEN are also acceptable.
The number following L, C, or R is the channel number.  Once this is all working (answering in English),
type in the following command to program the serial number:

UID CENTER:″B010200″
where you substitute the serial number on the top rail of your plugin for B010200 and LEFT or RIGHT for CENTER as appropriate.
No space between the colon and the  double quotation mark.




You can use all the same commands using GPIB.


You can use all the same commands using GPIB.




The response on the computer should be OK.  Check that the scope identifies the plugin serial number.  
The response on the computer should be OK.
Check that the scope identifies the plugin serial number.  


Mission accomplished, unless you have an 11A52, and that is the subject of another article.
Mission accomplished, unless you have an 11A52, and that is the subject of another article.




Remove the CAL-LOCK jumper from the mainframe. Reinstall the plugin jumper in the vertical position.


Remove the CAL-LOCK jumper from the mainframe.
Reinstall the plugin jumper in the vertical position.




And you are done. You can confirm the serial number and the firmware version on the mainframe (Utility button > Page 1 > Ident).


And you are done. You can confirm the serial number and the firmware version on the mainframe (Utility button > Page 1 > Ident).


Turn the mainframe off and restart.  If there are probe error codes, they can be cleared by installing a probe. 11A52s will still have an "HFAdj Cksum" or similar error code. The transient response on the 11A52 will not be corrrect until new constants are installed.  See elsewhere.


Turn the mainframe off and restart.  If there are probe error codes, they can be cleared by installing a probe.
11A52s will still have an "HFAdj Cksum" or similar error code.
The transient response on the 11A52 will not be correct until new constants are installed.  See elsewhere.




NOTE: John did this from memory so he hopes it is all correct.


NOTE: John did this from memory so he hopes it is all correct.




Dennis Tillman W7PF
Dennis Tillman W7PF
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