Alarm system alert said to replace 12V backup batteries, so I called my alarm system provider to send out a tech. When tech hooked up new batteries, smoke and an electrical burning smell enshrouded the security system panel that was in close proximity to the circuit breaker box, gas lines, and gas powered hot water heater and furnace. The smell was intense, but the smoke and smell then dissipated. Security system tech smelled the same, but found nothing wrong with security panel.
I called JAB, who came out that evening, which entailed an emergency charge which I was happy to pay, as I wanted to ascertain the source of the smell and whether there was damage to the circuit breakers in main breaker box, as it all wreaked of a fire hazard. JAB (Abraham) checked the circuit breaker wiring - all okay. Then he opened the security system panel and immediately found a burned power supply card. The security system tech had looked at the same power supply card multiple times, but missed the charcoal burn marks (as did I, since part of the card contained black fixtures). But Abraham noticed it within seconds. For safety reasons, he disconnected the security system. He also provided pictures and a write-up which will be forwarded to the security system provider. I definitely would call JAB again. Very competent and professional.