Very nice troubleshooting, 
Ok, my turn to ask... I have this quite early version of Carnivore2. It is green PCB that has power input pins cut away with pliers and sound output jack & EEPROM missing, if that helps to identify the exact version.
When Carnivore2 is connected I can hear this low cracking noise that sounds like the volume potentiometer on monitor is dirty (well, actually it is), but this noise is coming from the cartridge it self... It is not that bad that it would interfere when you play games, but when you do something else the noise slowly starts to bother...
My first question is: Is there some recommended hack for this noise problem?
Also 2nd question: I've updated the firmware to latest version to solve my CF compatibility issues, but what version of menu program would you recommend for devices that have EEPROM missing?
Edit: 3rd question: What is the meaning of the button near Cyclone II chip?
You can always buy a freshly assembled and fully updated Carnivore2 from one of our distributors.
You can always buy a freshly assembled and fully updated Carnivore2 from one of our distributors.
Well... Actually I'm very happy about that. My personal problem is that if I see something interesting I want to get it right away even if I don't have immediate need for it... This is because I've learned that if you don't do that after a year or two you usually can only regret your decision and you'll either newer see the product again or you end up paying "your grandmother and pile of strawberries" to get it (as we say in Finland) Here you have done really good job as the devices are still available, and you keep giving active support for them. Kudos for that!
Here is my whole story: Before lately I did not feel need to update my Carnivore2, but then I wanted to test Nextor "new" EMUFILE-command... and that required me to update the BIOS... After that it was all almost fine, but I found out that I get random read errors on my CF card... and that forced me to update the firmware... and when I updated the firmware I kind of assumed that I need to update the menu as well... and only after doing that I realized that I have the EEPROM missing.
... but this was not unique problem for me. On Carnivore2 update I needed to go trough all this how to get power -> "Cheap Chinese clone Blaster" -> No signed drivers for Win10 -> Ignore signing -> BSOD -> put Win7 drivers etc. show trough, so when I got it done I turned my head to GR8NET, that had very similar history... and I ended up to pretty much identical problems...
There I also had so old (0.3) firmware that it was not able to update it self at all, so JTAG-cable & external power was required... and after update I realized that now I'm missing stereo output and my EEPROM is ridiculously small.
Now that I got my update frenzy going on, I even ordered a pile of IDE to CF adapters in order to update all my Sunrise IDE & Sunrise IDE+RS232 adapters to this millennium... I even bought two more Sunrise IDE+RS232 adapters from local Facebook group as the common understanding there was that they are not good even for throwing birds as the police may give you fine if you do that... That got me a bit offended as I remember using them for years in late 90's and being a happy customer. So... Now that I already downloaded Nextor images for Carnivore2, my next weekend project is to get them to same level in sense of OS version and CF support as my Carnivore2 and GR8NET. Luckily these don't have a firmware that I would need to mess up with 
My major idea is that then I have plenty of "close enough" interfaces to plug in to my different MSX computers while being able to swap CF-cards freely between those interfaces, Sunrise CF ATA-IDE and Carnivore2... I have also SD->CF adapter so that I could share also GR8NET cards, but all of this needs a lot of testing and I can't say if my dream of "MSX unified mass storage" (other than floppy) will work out in reality, but at least in theory it should. (Oh, and now I realized that my MFR+SD will need update as well)
