[sdiy] Korg Delta problem

[Tom Wiltshire]

> On 19 Jun 2018, at 00:31, Gordonjcp <gordonjcp at gjcp.net> wrote:
> 
> As we all know, it's always the 4051 muxes... ;-)

...or the ni-cad memory back-up battery eating everything away! Or the failing “conductive” rubber contacts on the buttons/keyboard/somewhere else important.

But no, the caps isn’t the first thing I look at either!

Going back to the Korg Delta for a minute, I’d start by opening it up and then (carefully) turning it on and testing all the power supply voltages to make sure they’re in spec. Then leave it for however long it takes to go weird. Then test the power supply voltages again and see what (if anything) has changed. If you can’t get it to go weird with the lid open, it’s almost* certainly an over-heating problem. If it does go weird, then you’ll know if it’s the supply that’s causing it.

Tom

* I once had a strange fault with a broken switch connection, and when the synth had the lid open, the broken bit of metal inside the switch fell to the back and made the connection as it was supposed to! That took some finding!