Air-Sea Battle acting weird on my Sears Video Arcade unit

[gmaletic]

I recently purchased a Sears Tele-Games Video Arcade console off eBay. It generally seems to work fine, but I notice that on Air-Sea Battle I see a very consistent problem: after playing for ~30 seconds, an "explosion" sprite appears onscreen that keeps the game from advancing. (This happens both with the Air-Sea Battle cart I own, and when I load up airsea.bin via a Harmony cartridge.)

 

Has anyone ever seen anything like this before? Is there something defective about my console that would cause a consistent problem like this?

 

Thanks.