Harman Kardon AVR 7500 Front right channel problem

Guest · Posted: Sat Nov 08, 2014 10:34 am Post subject:

And checking the block diagram, then it looks to be the electronically controlled volume control. So IC706 is the bad guy here... Need to check the solder points as this is not an SMD component.

If these does not change anything then I will replace the item.

jts1957 · Joined: 24 Nov 2008 Posts: 2476 Location: Far, Far Away

You will need to 'float' a single IC pin.
Picture a 'dot' centered inside a 'circle' :

The 'dot' is the IC pin and the 'circle' is the PCB foil AFTER successfully removing the solder so they are no longer electrically connected together.

Pin 26 of IC706 is Output
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Guest · Posted: Sat Nov 08, 2014 10:19 pm Post subject:

Sadly IC706 is an SMD component afterall, so floating one point is not as easy as I would have liked it to be. Sad

jts1957 · Joined: 24 Nov 2008 Posts: 2476 Location: Far, Far Away

So that leaves: hoping to find a through hole part in series with the foil trace you need to isolate; looking for a easier part/point further forward or behind the part/point first intended; purposely cutting trace and repairing it afterwards or IF your soldering/dexterity is up to the task, 'gull-winging' the lead. IF lifted too high risks breaking off. Too little heat or trying to lift to soon, breaks trace; too much heat could result in damage to the trace/part.
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