Just doing a quick write up of a powered mixer repair that’s going out today. It’s a Wharfedale repair, an SPX815 powered mixer that had no sound output from the left output channel.
My first instinct when the Newark customer contacted me was to expect that the output stage had blown, but this turned out not to be the case as I quickly discovered that the left channel was fine when a signal was plugged straight into the power amp inputs.
It’s difficult to attempt a powered mixer repair without schematics so I’m very grateful to the gentleman on a forum who sent me the schematic over. After tracing the fault through the schematic I discovered that an SMT op amp in the left channel graphic EQ was blown – there was a nice neat hole in the top.
Someone had already attempted a repair on the PA section of this amplifier – I’ve no idea what they were doing, but they’d bent the metal chassis around the PA, stripped the threading on a PEM and tried to hold the whole botched job together with a wood screw. It’s pretty much impossible to bend things like this back, but I did my best, redrilled the mounting holes and replaced the dodgy wood screw with a machine screw! I left a note to any future repairers so that no-one things the dodgy work was done by was me!
Here’s a video of the powered mixer repair:
If you need a powered mixer repair, please get in touch.