[sdiy] wavestation backlight whine hack

[nicolas]

Hello

Just in case anyone here is interested I thought I would relay a simple hack just completed ...

I have a Korg Wavestation EX with dead backlight, which had the annoying whine that so many of them have now.  I don't really need the backlight enough to be bothered fixing it properly, but the whine was really annoying.  The whine is from the inverter that powers the backlight.  Disconnecting the dead backlight raises the pitch of the inverter to be less annoying, but doesn't stop it.  I read on the net that one person went so far as to remove the relevant transformer, but that seemed a bit drastic, required getting the board out of the synth and a pain to reverse if I ever wanted to return it to original.

A much simpler fix is to cut the power supply to the inverter.  This can be done without removing the board.  The inverter in the EX is on the power supply PCB in the corner opposite where the mains comes in.  The DC power to the inverter arrives via a wire link that can be cut without having to remove the board from the synth.  Cutting the link fixes the whine and is also easily reversible if you ever want to return the backlight to original.

To open the wavestation flip it over and undo all the screws on the bottom.  There are a lot.  Then slide that bottom panel away from the back panel and lift it off.

To identify the wire link, look for the small transformer in the corner of the power supply PCB opposite where the mains comes in.  Just to north of it there are some big electrolytics, to the east the connectors taking power to the synth, to the south a small cap and a small transistor.  And to the west of it a wire link then a couple of resistors, all quite close together.  That wire link between the transformer and the pair of resistors is the one to cut.  Its a bit fiddly to cut because it is so close to the transformer, but easier than removing the board.

Cheers,
Nicolas