[volt-nuts] 7081 calibration "Zero too large"

[David C. Partridge]

Thanks to a very kind gentleman, I received in the post today an Itron FG209C2 VFD and an ER-3400 NVM for my ailing 7081.

Naturally, it is still unwell even with these parts fitted, and getting it working will clearly be a labour of love.

I issued a calibrate,zener,103 and received in return a "Cal incomplete" message.  Power off followed by initialise also gets me a "Cal incomplete" message to it looks like the new NVM is OK - yippee!

When I then try 

calibrate,vdc=0.1,zero

I get a "Zero too large" error message so there's clearly still a fault on the floating boards. Mrs. Murphy said (*) that it would still have problems even after replacing the display and NVM, and boy was she right!  Clearly it will be a labour of love to get this working again!

If anyone has any suggestions as to what is likely to be causing the "Zero too large" error, I'm all ears!

(*) Mrs Murphy's law: Murphy is an optimist.

Thanks
Dave