Broadcast & Communications Engineering and Maintenance Services
WRLA Studio Audio Cable Troubleshooting and Repair – October 5, 2021
A problem has mysteriously developed whereby one channel of the stereo audio from the WRLA Automation PC going to both the Autogram console/automation switch and the Arrakis on-air console was getting knocked out and only having noise on it when the cable running from the PC’s audio card output (via a splitter) to the Autogram switch. After a little troubleshooting time, I discovered that an intermittent short-circuit was occurring between the red conductor/wire to the shield/ground on the balanced audio cable running from a terminal block to the input plug on the Autogram switch.
These five wires connected to the terminal block were contained in a balanced stereo cable running to the input plug on the Autogram switch. Not seen in the photo are the terminals on the right-hand side of the terminal block, which is where the audio coming from their automation PC (via a splitter.)This 5-conductor plug is the input plug for the Autogram switch. With the audio cable disconnected from the automation PC’s output splitter and the Autogram input, I found that the red wire/conductor was intermittently shorting to the bare shield/ground wire. I tried trimming back the cable in case the jacket of the red wire had been perhaps nicked during installation, allowing an intermittent short-circuit to the shield/ground. That did not resolve the problem. The problem was solved by replacing the entire cable from the terminal block to this connector. After doing that, both the left and right channel audio was working correctly both in the Autogram switch and the Arrakis audio console.
Exactly *where* along the cable the short-circuit was occurring was not determined. That’s one of those relatively pointless (not to mention time-wasting) activities that you just say “Nahhhhh” to. Instead, you just grab a fresh piece of cable, route and terminate it as needed, and toss the old piece of cable in the trash. Who knows how long the problem had been occurring. But that problem has been put to bed.
