@narenvemury no matter what voltages you have showing right now, you know it's not enough. does not matter if it is 0.1V or .006V The variance i most likely caused by your meter but it's really only academic. You will need to try to charge your battery and see if it will hold a charge or replace it, which is most likely. Your battery sounds like it has been discharged below the threshold of taking a charge..
Now, your device should turn on if you use a 9.5V AC adapter, even with the bad battery. If it does not use troubleshooting flowchart from the Sony DVP FX810 SM.
P1 is the power fuse on the main board and D2 is the power diode on the main board as well.
You can download the SM from this page Sony DVP-FX810 under the Documents tab
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