Your +12V line is well out. At just 9.59V, it is 2.41V (-20%) below the nominal value. This deviation from the nominal value is enough to cause problems such as random shutdowns. Before condemming the PSU, you need to verify this voltage level by backprobing the main ATX 20/24 pin connector. Using a digital multimeter set to the DC voltage range (auto-range preferred, but if not available the 20V range), insert the black test lead into the connector of any of the black wires and the red test lead into that of any of the yellow wires. Make a note of the reading. If it reads less than 11.04V (-8%) or more than 13.20V (+10%), then the voltage is out of tolerance and as such the PSU will need replacing. To eliminate possible problems caused by an internal fault on an HDD/optical drive, disconnect these prior to the test and also disconnect all fans (apart from the CPU fan) for the same reason. If the reading is normal (within the range 11.04-13.20V), then reconnect one item at a time and retest. The faulty item will cause the reading to become out of range (typically below the lower limit). Check by disconnecting it and retesting.