AV Receiver shuts down

[manic_biker]

My AV receiver randomly shuts down, preceded by a very loud popping sound (presumably the cause), ONLY when watching TV. I have a Hauppage Quad TV PCI card, installed in a Win 10 PC. TV signal is derived from an attic-mounted antenna/LNA, with two layers of cable surge protection. The PC output is routed to the AV receiver with HDMI. That same HDMI interconnect is used for streaming Netflix and Prime, with no issues. I also have an external Blu-Ray player connected to a second HDMI receiver input, with no issues.

Can anyone offer any suggestions and/or tests to pinpoint the problem?