Scantronic 9751 - Default Engineer Code doesn't work!

[Gazmo1]

I have replaced the battery via the following steps from the manual:-

Removed mains power (silenced alarm)
Removed lid
Removed battery (old)
Applied NVM & K/S jumpers to short the pins
Connected battery (new) – Silenced alarm with default code
Replaced lid

On the 9930 control display I have:

LID TAMPER (then)
RESET REQUIRED (repeatedly)

But default Engineer Code 7890 does not work!!!

I have tried the process twice with no joy.
I assume the tamper switch works, it's just the engineer code reset I require but the default '7890' just gives me an "invalid code" on the display.

Any ideas?

Thanks in advance.

 

[Neil a]

Found this

 

[Neil a]

Think you have to key in 0 before code