Serial TX/RX simultaneous, nothing connected

[CReese]

Hello all,

Been quite some time. Quick question: I have a CPU that is showing RX inqueue (and on LED, obviously) on the H2-DM1E internal serial, each time a message is transmitted, even with nothing plugged in. I have to guess that the install guys fried it somehow. Is this a predictable and obvious failure mode? Is there any way to produce this result other than a hardware failure?

Cheers,
C

[plcnut]

Have you looked into the jack to see if the pins/wires are physically bent and touching? I have seen this happen before...