You appreciate that, kind advice notwithstanding, 'tain't a CUDA in G4 towers but a PMU, so treating it as a CUDA just flattens the battery overnight. Your clicky, clicky, flashy sounds just like a failure of TRKL in the power supply. It's either deep delving and surgery for you or a new PSU. Before desponding, measure the output voltages from the PSU at the MLB connector and compare them with spec.
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