Keithley 2410 turned into 2400 while being used in the production line.

Has anyone experienced the phenomena before?
What was the problem and how was the matter resolved?

Can you elaborate on what you mean by it turned into a 2400?

How does the instrument respond to the *IDN? command?  The model number is part of the response string.

Production was using it as 2410 when, according to them, not too long ago into turned to 2400. The *IDN? query showed the unit as 2400.

I did not mention earlier, that upon power up the unit will momentarily show Error 603, Power-On State Lost. I have checked the voltages +/-5V, +/-7V, +/-15V, +/-42V, +/-70V, are all present.

I have checked that the board indeed was designated as 2410 and the ICs U15 and U16 are consistent with 2410. The board label is printed as 2410-140M Dev9292.

I have tried re-flashing the firmware (C32) by using the "press the CONFIG key while powering on the unit" and choosing the model 2410. The unit still showed model 2400 and the error 603.

What is the serial number?

If you hold down the toggle and sweep buttons while powering on there will be a secret menu to set the correct model. Menu->General->Secret
 

Thank you Andrea and John for your replies.

The s/n : 1200551

I've tried the Secret menu but it reverted to 2400 upon power cycle. I tried Secret menu to change the model to 2410 and re-flashed the eeprom and firmware before power cycle. After successfully Re-flashing these for 2410, upon power cycle it reverted to 2400.

I suspect the clue to this problem is the error 603 Power-On State Lost notification. I will research on where the model number is being located, I believe in another eeprom and work around that area,