Just picked up a used Syncrowave 250dx last week. I've been happily test welding with various settings and materials. I'm new to TIG welding.

It was time to try the Pulser feature. However, pressing the On/Off button on the Pulser does nothing. No indicators turn on.

Is it broken or am I missing something?

If broken, where do I begin to diagnose and repair it (assuming I can afford to)?