You verified all the traces of the 2610..you replaced the caps,correct?
Replace the amp.
BTW I've replaced certain caps in the audio section before which has solved the problem you have now so don't rule out replacing them in the future.
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That's because you missed this
https://www.neo-geo.com/forums/index.php?threads/stoneagegamer-and-terraonion-pre-orders-for-neosd-pro-aes-mvs.270054/page-4#post-4510327
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Because it's the main processor..
They're not known to be unreliable BUT I have had to replace two or three in the past.
In the meantime,is your bios (531024) stock?
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