About Supply Input To Power IC
Voltage testing is one of the fastest way to determine if a particular section or a component have problem or not. Whenever there was a complaint of no power in an equipment, the first thing i check was the fuse. Next i can either check the supply input to power IC or the output voltages from the SMPS. If there is zero voltage at the output then most probably the primary section is the cause of the problem. For your information, have supply input (VCC) to the power IC does not guarantee that the IC is working. It could be the internal part of the IC have open circuit or something external that had caused the power IC not to produce output thus causing no power symptom.
In your case you can either direct replace the power IC and retest or check all the components in the primary side (assuming you have check the secondary output diodes and found all to be okay) and then only you replace the power IC assuming you found no bad components in the primary section. You may use the method i just explained to troubleshoot any consumer electronics SMPS.