In this episode Shahriar investigates a failed Rohde & Schwarz AFQ100A I/Q (ARB) Modulation Generator. This instrument provide differential I/Q outputs with exceptional SFDR which makes it ideal for various wireless system testing. The instrument shows a stand-by LED but does not power on.
The problem is tracked to the main power supply’s soft power-on circuit. After the repair of the power supply, it becomes clear that the main HDD is also defective. An identical donor drive is used to repair the broken HDD main controller board. A full teardown of the instrument is also presented. After the repair, the instrument is used to generate various arbitrary waveforms for performance verification.