Although I get the "Boot Up Beep" the unit doesn't make any sound, can't be unsquelched. May be an indication that it hasn't quite completed the boot up process, despite the initial beep.

Hi Jry, thank you for your reply & happy new year too!
I'm based in New Zealand. Did contact both General Dynamics & Freedom Communications to obtain a service manual. General Dynamics sent the operating manual for this unit which is still handy to have. ( Hard to locate the correct one for the LCD ...

Thank you so much for the explanation. It was very helpful.

I have figured that both the Epson LCD controller IC and the Motorola Power PC IC is available on Ebay if required.

I have BGA removal/ replacement facilities & experience if the Power PC processor or the LCD controller needed replacing ...

Thank you for your reply. Does the "Beep" suggest that the processor board is faultless?
The other board with the display interface seem to be the faulty one & I'm trying to find the fault on it. It seems to have more things than just the display interface, when it is disconnected, the unit doesn't ...

I have a R2670B with no display. It is the version with the LCD display & apart from blank display or vertical lines on display sometimes immediately at power on, nothing else on display. It needed a new memory back up battery, which was replaced. The main processor board wasn't damaged by battery ...