The owner reported the game stop booting up. No graphics and no signs of life. I offered to take a look and attempt repair.
After confirming the game was not functioning I searched for a Donor cart. Often transplanting the ROM (game program) to a new board is simpler than diagnosing and repairing the board.
Earth Bound uses a SHVC-1J3M-20 board. Luckily this board is shared with more common and cheaper games.
Games that use this PCB type:
Breath of Fire II
Dai-4-ji Super Robot Taisen (Super Robot Wars 4)
Dragon Quest III - Soshite Densetsu e...
Fire Emblem - Seisen no Keifu
Gakkou de Atta Kowai Hanashi
Human Grand Prix IV - F1 Dream Battle
Illusion of Time
Romancing Saga 3 (ロマンシング サ・ガ3)
Secret of Evermore
Seiken Densetsu 3 (せいけんでんせつ３, 聖剣伝説３)
As you can see my copy of Dragon Quest was not compatible. Hopefully this news will help others update the donor database. All list suggest Dragon Quest VI was a SHVC-1J3M-20. I had to reorder a new donor cart but this time I selected NHL 97 and it was a perfect match
Next step is to Desolder the ROM chips. Specialized tools are required for this step. This can be difficult for most home hobbyist.
Earthbound ROM soldered onto the NHL 97. Soldering is clean and matches the factory look as much as possible (I'm not a robot)
Next step is testing in the SNES console....
Fixed! Game booted up perfectly! I rescued a $200+ collectible SNES game with a $5 NHL 97. Awesome!
Later I will replace the old Game Save battery and return this to the owner. He was trilled to have his game revived.