Embodiments are generally directed to phase lock loop bypass for board level testing of systems. An embodiment of system includes a power management block for the system; multiple IO (input/output) blocks; a phase lock loop (PLL) block for each of the IO blocks, each of the phase lock loop blocks being switchable between providing an output of a PLL clock signal or providing a replacement clock signal as clocking for the respective IO block; and a read only memory for storage of firmware. In some embodiments, the firmware includes elements to enable operation of the plurality of IO blocks utilizing replacement clocking.