We take great pride in having almost zero failures of our products.
Occasionally, I get a trouble call from a new 5009 frequency synthesizer user who says that the 5009 will not lock on frequency after power up. Usually it’s just one of the RF Sources that won’t lock. After doing some investigation the problem almost always is caused by the power supply. The power supply is usually a standard lab bench supply like this Keysight/Agilent E3611A:
Figure 1 Lab bench power supply can cause problems if you "dial up" the voltage.
The power supply is not the problem nor is there anything wrong with the 5009. The problem is how the power supply is set up and used. Follow these suggestions to make sure you don’t run into start up problems: