Vintage Synth Repair

----- Original Message -----

From: Quazimodo

To: vintagesynthrepair@yahoogroups.com

Sent: Wednesday, July 18, 2012 12:27 PM

Subject: [vintagesynthrepair] Re: Backlight Revisited...

Before I do something stupid, or blow something up - can I measure the 400Hz with the frequency counter on my digital meter, to see if it's there...?

Cheers,
TOM

--- In vintagesynthrepair@yahoogroups.com, "65 Lotus" wrote:
>
> 100 VAC @ 400 Hz.
>
> http://retroactivesynth.com/index.php?page=backlight-mayhem
>
> ----- Original Message -----
> From: Quazimodo
> To: vintagesynthrepair@yahoogroups.com
>; Sent: Monday, July 16, 2012 7:53 PM
> Subject: [vintagesynthrepair] Re: Backlight Revisited...
>
>
>
> I was told that you cannot/should not measure the voltage with a meter... but to use an a/c checker, like the neon screwdriver, which does light! As the neon lights I can hear the transformer start to buzz.
>
> There is one small transistor assocated with the transformer. Haven't checked it's temperature - should it be getting warm?
>
> Also what should the frequency of the a/c output be?
>
> Thanks for the suggestions guys.
> TOM
>
> --- In vintagesynthrepair@yahoogroups.com, NoëlBuhagiar wrote:
> >
> > Hi,
> >
> > You could have low voltage at step-up transformer output.
> > Transformer could have developed shorted turns.
> >
> > Do the oscillator transistors get hot?
> >
> > Good luck,
> > Noel
>; >
> >
> > From: Quazimodo
> > Sent: Monday, July 16, 2012 6:52 PM
> > To: vintagesynthrepair@yahoogroups.com
> > Subject: [vintagesynthrepair] Backlight Revisited...
> >
> >
> > Hi folks,
> >
> > I wonder if anyone has any ideas about this one.
> >
> >; I bought a new backlight for this Korg Wavestation EX... it didn't work. I checked the pins on the power supply feeding it... and it lit up one of those neon A/C test screwdrivers.
> >
> > So I assumed the light was faulty and got a replacememt. Today I wired up the new backlight - on a loose wire, just to make sure it works and... nothing!
> >
> > I am getting power on the connector... and I have two backlights that don't light on it.
> >
> > Any ideas/suggestions please...?
> > Cheers,
> > TOM
> >
>