Chart display blanks out sections

[Njlarry]

Often my old vintage 99 Raymarine chartplotter blanks out sections of the display. It will change with any zoom in or out. There is a slot for a C card but I don't think there is a card in there.
Anyone know the reason? Please no Garmin is better debate. The old Raymarine is what I have and need to keep it as it is also the radar display.
Thank you for any insights.

 

[Skybolt]

That is caused by no chart data available at that zoom level. You are at the edge of the chart limit or just no data. There may be more data if you zoom out or not, but that is the chart's limitations. My friends did that as well and he bought a new chart card that covered the area's he was interested in and that fixed it. But not all area's are available for your year plotter.