Amplifier Connector Fuzz

Problem:    Lots of noise on left speaker channel
Solution:   Solder new photo jack
Brand:
Cost new:   £350
Cost of fix:90
Age:
Success?:   Yes

This was very fun to fix!! This audio amplifier came in with the customer saying that the left channel was very noisy and it had slowly been getting worse.

Usually when there’s audio coming through that’s correct but it’s very noisy it’s a ground loop or grounding issue. The speaker isn’t being driven with a proper ground reference. Looking at the connector and doing a continuity test from the back of the connector on the PCB, everything seems to be connected and working so I started looking at the board to see if there was a component that had failed.

Nothing looked wrong or damaged so I double checked the connector itself. Turns out, the tab for the ground connector wasn’t connected to the main chassis ground!!! This was very confusing, so I got the PCB out of the enclosure and looked at the soldering connection which looked fine.

But when testing the continuity between the photo socket itself and the solder joint, the ground connection wasn’t connected!!! I soldered a wire connecting the ground on the connected directly to the PCB and all the noise vanished on the left channel!

I desoldered the connector and when removing it, I realised that the tab had entirely snapped off and that’s why the left channel wasn’t being properly grounded!

Ordered a new one for 90p and soldered it and it worked like a charm.