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Check if the clock and data serial lines shared with SODIMM-A/B are healthy (compare diode mode readings with good board, check pull up resistor value, trace continuity)
I had one liquid damage 2936 or 3115 board, fucked bklt chip LP8850 pulled down one of the SCL/SDA data line and had the one beep no RAM.
If there is voltage on L7330, then this is some drop that won't get fixed. If you don't have voltage on L7330, then probably a dead U7300. What voltage is on L7330?