Mario Bros. repair log

From: David Shoemaker <davids_at_oz.net>
Date: Sun Sep 09 2012 - 22:00:07 EDT

Mario Bros. board

 

Game hangs with corrupt screen, reboots, crashes. Just basically borked.

 

Replaced Z80A on main board, game now runs.

 

 

Second problem:

Unless +5v turned up to 5.20 or higher sprites corrupt (chunks missing /
wrong on opening logo, sprite noise in normal game play).

 

Sprite ram is @ 8B&C on video board, tried piggybacking 2114's no change.

Piggybacked 74ls273 @ 8D, corruption gone. Replaced 8D board now works fine
at 5V.

 

 

Determined 2114 rams at 8 B & C are sprite rams (shorting data pins showed
sprite corruption)

Determined 2114 rams at 3 D & E are background roms (same shorting showed
background corruption)

 

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Received on Sun Sep 9 22:00:24 2012

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