Got always from Portugal this Alien PCB:
As often happens on this hardware the sprites had jailbars thru:
Board uses 4Mbit MASK ROMs to store GFX (sprites and background) data that are quite prone to failure.I launched a MASK ROM check that reported a bad device @K8:
I removed it and my programmer warned me about pin 13 (data line D0).I tried the dump in MAME and I could reproduce the issue :
I replaced the MASK ROM with an equivalent 27C400 EPROM :
This fixed issue and board completely.End of job.