Unlocking Agilent U1732C/U1733C LCR meter features on cheaper U1731C

[ArcticGeek]

I had seen some time ago that a few people were able to somewhat "unlock" some of the features on the higher end Agilent LCR meters by modifying the serial EEPROM, as seen in this thread:

https://www.eevblog.com/forum/projects/agilent-u1241a-to-u1242a-hack/msg203666/#msg203666

I'm curious, did anybody ever have any real success in doing this?  According to the posts in the above topic it seems that people were having some difficulties getting the higher 10Khz and 100Khz modes working properly. 

I have a U1731C that I purchase recently, and I'm quite happy with it.   I use it mostly for measuring ESR of electrolytic caps, so the limitation of the 1khz doesn't really bother me. 

But I would like to enable the LED backlight on my U1731C, that model doesn't have one.  I have a feeling that it is simply a software enable feature, as the LCD displays between all 3 models look identical.  Even though the Keysight part number is different between all 3 models according to their parts website, I find it hard to believe that Agilent really has 3 different part numbers for it.  It makes more sense to me that they have simply disabled it in code.  If I press and hold the key that is supposed to be the backlight key it just beeps twice; indicating that you have pressed a wrong key. 

Has anyone tried to "upgrade" their U1731C to the higher end models?  Did it work?   Does the backlight work?