Front Panel Screens - Hog 4 Consoles

Hi there, I have 2 x Hog 4 Consoles here, both ran low on Bios batteries and now I have no working middle front panel displays. It is worth pointing out that the screen issue coincided with the battery drain (during last year). The touch panels themselves respond to touch input but there is no display image and the screen appears to have a working backlight. I have also seen this issue on other Hog 4 Consoles in other rental stock in the UK. Is there a known resolution for this please? I have replaced the BIOS batteries and all else is perfectly fine with the consoles. The hardware is running 3.17 and has been 'Full Install' updated from a much earlier build. Please help as soon as you can, I am onsite and would love full use of the consoles...... Many Thanks.