MacBook Pro 2012 not powering on

MacBook Pro 2012 is not booting at all. The charging light is green when connected, however the fans don't spin, there is no chime, and the drive does not spin.

Points:

• Reset of SMC and NVRAM
• Held power button for 30+ seconds with / without power / battery plugged into logic board
• Removing all connections from the logic board, and testing each component while trying to turn on
• The internal components/logic board appear clean and undamaged
• Check power button cable - all fine
• No liquid damage / all water spots are untouched

*

The last thing I could try would be to ensure the board is receiving power with a multimeter, I have one but have no idea where to put the connections for testing.

Any suggestions would be appreciated.