GC 6890 no valid serial number (without any change)


we didn´t use our old (2006) GC 6890 for a couple of months. We had no problems before, but after new start today the display showed: "version N.05.05" and "no valid serial number". 

With Options - Diagnostics - Instument Status I found the serial number US00000000 instead of our CN10... and manufacturing date was "unknown".

I guess we have problems with our mainboard, because I found this in the forum:


"After replacing the 6890A or Plus Mainboard, the serial number of the GC must be restored from the front panel. The 6890N Serial number can be restored from the front panel or via the GC Firmware Update Utility. To re-configure the GC serial number: 1. Press [Options], then select Diagnostics/Instrument Status. 2. Press [•] [•], 3. To change the numerical field, type in the GC serial number (shown below the GC keypad), and press [Enter]. 4. To change the country of manufacture, press [Mode/Type] after pressing [•] [•]."

I tried this, but pressing [•] [•] didn´t cause any reaction, the display remained unchanged.

Does anybody have an idea what could be the reason for our problem and how to resolve it?

Thanks for your answers.

  • Now I managed to change country code and serial number. The description was also in this forum:

    "Reset the serial number in the firmware.  go to:

    • Options
    • Diagnostics
    • Instrument Status

    As I recall you need to have the cursor on the serial number line, and then depress the "." (decimal) key.  You should then be able to enter the numerical portion of the serial number.  I believe if you press the "Mode/Type" button you can change the alpghabetic country code."

    I will see if the GC works or if this was only a part of a bigger problem.

  • Dear !

    On the mainboard, you can see a 3V battery, located in the lower left corner. If the GC was not in use for a long time it is possible the battery is low. The battery supplies the power to retain user entries in memory, such as programmed methods and sequences and even the serial number. If the battery is low the GC forget the serial number.

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