Astya Nax Repair Logs

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Repairer: Paul Swan

BOARD NO: 0017
GAME: Astya Nax
MANUFACTURER: Jaleco
DATE: 1989
HARNESS: JAMMA

SYMPTOM (27/04/96)



(1) Foreground characters were corrupt.
(2) Some control inputs didn't work.

SOLUTION



(1) The forground characters responded to flexing of the board and using the pulse injector on the ROM data pins indicated that ROM23 held the forground characters. Checking the adrress bus of this ROM with a logic probe identified pin 8 as being always high when the fault was evident and pulsing when the video operated correctly. Tracing this pin back from the ROM board down onto the mother board to it's origin in a SMT "OBJ" device indicated nothing wrong with the trace but a couple of pins on the "OBJ" device were lifted. Tacking these down with a soldering iron fixed the video.

(2) One of the three JK03 custom input multiplexors was damaged. Having no replacement, the device was removed and small wires tacked onto the pin stubs that were still accessible. The device was the re-fitted and all three JK03's were secured with epoxy resin to prevent further damage. This fixed the game.