Skip to main content

Fix Your Stuff

Right to Repair

Parts & Tools

Help

Original post by: IanCD ,

Text:

Here is my 2 cents worth on fixing Audio Amplifiers/Receivers:

Many use single sided PC boards for the analog sections.

Output transistors and connectors are mounted onto sub-assemblies (e.g. heat sinks) and the leads soldered into the PCBs. Over time, vibration and thermal expansion/contraction cause the leads to push the the solder joint and underlying PCB trace off the single sided board. The trace cracks and you get intermittent or no connections across the break.

I have had this issue with two Sony and one HK 5.1 receivers in just last the couple of months.

If you feel comfortable working around high voltages (120V DC is not unusual for high power amps)- take off the access panels and tap around the single sided boards with a NON-CONDUCTIVE probe. If you are lucky you will identify the broken joint. You can then power down, WAIT FOR THE SUPPLY CAPACITORS TO DISCHARGE (remember you can still get zapped even a long time after the power cord is disconnected!) then re-solder it.

I'm also an EE, but fixing audio is just a hobby ;-)

Status:

open