[sdiy] Korg Delta problem

[Gordonjcp]

On Tue, Jun 19, 2018 at 01:07:43AM +0100, Tom Wiltshire wrote:
> 
> 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.
> 

Now we're kicking it oldschool!  Get in there with the hairdryer and the
freezer spray, just like back in the day when TVs used to be repairable
:-D

> * 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!
> 

A guy on the Range Rover forum I run (one of the co-founders, really)
had a weird misfire on his daugher's car.  It would run perfectly under
load with a decent amount of throttle, but on a trailing throttle or at
idle it had a dead miss on one cylinder.  Well it's got to be fuel or
sparks, right?  Took out all four spark plugs, held them up to the light
to check the gap, gap's perfect.  Stick 'em back in, same.  Take them
out again, noticed that one of them "clicked" as he turned it over.

THe central insulator had broken up inside the threaded part, and when
it was pointing downwards the electrode sat on top of the earth
electrode.  Presumably with the higher cylinder pressures under load it
was bouncing the electrode up far enough to get it to spark.

No, I doubt I'd have guessed that either.

-- 
Gordonjcp