----- Original Message -----From: QuazimodoSent: Wednesday, June 06, 2012 7:17 AMSubject: [vintagesynthrepair] Re: Korg backlight problemThanks for the reply.
Is there any way of confirming that the little transformer is shot.
Should it be o/c with my meter?
There is also a small transistor (2SC1815) feeding the transformer that could be suspect..!?
Cheers,
TOM
--- In vintagesynthrepair@yahoogroups.com, "narfman96" wrote:
>
> You should have around 100 volts ac on the plug coming from the inverter. It can be quite a bit higher if there isn't any load. Plus you should be able to hear the whine of the inverter.
>
> --- In vintagesynthrepair@yahoogroups.com, "Quazimodo" wrote:
> >
> > Hi guys,
>; >
> > I am looking at a Korg Wavestation EX with currently no backlight. I bought a new backlight foil and installed it - but still no joy.
> >
> > I checked to see if the volts were there on the small plug feeding it and there's nothing.
> >
> > Can any one confirm for me please what voltage I should be getting? And also, would anyone know what could be a common fault on these for a lack of volts here?
> >
> > Cheers,
> > TOM
> >
>
Message
Re: [vintagesynthrepair] Re: Korg backlight problem
2012-06-06 by jammie
yes the transistor could be the problem but also
the inverter coil
you should be getting an ac voltage from the
inverter coil
the transistor is a switching circuit which with
caps makes a fake ac ripple wave the inverter coil this takes the small voltage
ac wave and
up transforms it to a high voltage ac wave but low
amps
this voltage can range from 150vac to 400vac
depending on what transformer is used
there is a member on here who found a lcd led
backlight replacement and you can do away with the transistor and coil and fit a
current limiting resistor across the inverter and use the original cables for
the lcd display
if you look a few messages back about efoils you
will see it
it will save you time in loking for the fualt and
at £30 the lcd led backlights are cheap