Repair log: Lack of sprites, where problem is on the CPU board and not the video board. Test to make sure pin 15 /BUSREQ of the Z80 DMA controller is pulsing. If not, the DMA controller is not running (ie. not requesting the bus). Replaced Z80 DMA controller, sprites now working.
Notes: The CPU part list shows the sound MPU as an 8039. But it does not appear to be a stock 8039. Instead it appears it is a 8039 variant from the 80xx MPU series and might have some internal ROM programmed. Which means a stock 8039 cannot be used in its place. I'm still searching for more information on this and a replacement alternative. Without this chip, there will be no music or sounds (except walk which is an analog sound).
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