Vintage Synth Repair

No cracks - all looks fine.
Seems no matter what I change or do... it stays the same...;c(



--- In vintagesynthrepair@yahoogroups.com, "jammie" <jammie.emma@...> wrote:
>
> have you got any cracks on the pcb as i have had wavestations psu crack on the fixing holes
>   ----- Original Message ----- 
>   From: jammie 
>   To: vintagesynthrepair@yahoogroups.com 
>   Sent: Monday, August 06, 2012 11:43 PM
>   Subject: Re: [vintagesynthrepair] Re: Backlight Revisited...
> 
> 
>     
> 
>   that with in tolerance
> 
>   the circuit is only a few resistors 1 switching transistor and 2 caps and the step up transformer
>     ----- Original Message ----- 
>     From: Quazimodo 
>     To: vintagesynthrepair@yahoogroups.com 
>     Sent: Monday, August 06, 2012 11:13 PM
>     Subject: [vintagesynthrepair] Re: Backlight Revisited...
> 
> 
>       
>     Yes Jammie, I am getting the 5volts... well, actually around 5.5v
> 
>     ...it's weird one this!
> 
>     --- In vintagesynthrepair@yahoogroups.com, "jammie" <jammie.emma@> wrote:
>     >
>     > are you getting 5v at the incoming circuit or is this voltage higher
>     > ----- Original Message ----- 
>     > From: Quazimodo 
>     > To: vintagesynthrepair@yahoogroups.com 
>     > Sent: Monday, August 06, 2012 10:39 PM
>     > Subject: [vintagesynthrepair] Re: Backlight Revisited...
>     > 
>     > 
>     > 
>     > Hello again,
>     > 
>     > OK I swapped the smoothing Capacitor C28.
>     > 
>     > No change... so to date I have checked the transistor, C28 and also the actual foil itself.
>     > 
>     > Stil getting 166 volts AC at around 2kHz.
>     > 
>     > I was thinking of changing C26 and C29 as well - could either of these be causing the symptoms?
>     > 
>     > Also, the transformer itself... it is obviously 'working' but do these either work or not - can they give different results?
>     > 
>     > I know you suggest going the LCD route - but as I have already got two new foils, I'd really rather get it fixed if at all possible... but this is fast becoming an epic saga!
>     > 
>     > Cheers,
>     > TOM
>     > 
>     > --- In vintagesynthrepair@yahoogroups.com, "jammie" <jammie.emma@> wrote:
>     > >
>     > > check the smoothing capacitor c28 the transformer is fixed uptransforms to the correct voltage for input 
>     > > 
>     > > so if the input ac voltage is wrong then it gets multiplied by the transformer
>     > > 
>     > > so the input voltage to the transformer has to be wrong
>     > > 
>     > > the transistor switches the dc voltage of 5v into a small ac voltage 
>     > > 
>     > > its the same with all efoil invertors except on the korgs they have the components on board a lot use inverter chips which are the same but in a white box this is so if the invertor fails you can just swap it out 
>     > > 
>     > > on the korgs you have to find which parts are at fualt and change them
>     > > 
>     > > i would just remove the invertor circuit and fit an led lcd instead 
>     > > 
>     > > then all you have todo is put a current limiting resistor to the manufacturers specs for the led back light from 5v line to the + of the efiol output pin on the psu
>     > > 
>     > > then you can use the same cable for the back light as the original efiol cable
>     > > 
>     > > the led backlights from rs work just fitted one to a kurzweil k2000
>     > > 
>     > > which uses the same footprint as the wavestation but the negative blue ones are on back order until november 
>     > > ----- Original Message ----- 
>     > > From: scott frye 
>     > > To: vintagesynthrepair@yahoogroups.com 
>     > > Sent: Sunday, August 05, 2012 2:49 PM
>     > > Subject: [vintagesynthrepair] Re: Backlight Revisited...
>     > > 
>     > > 
>     > > 
>     > > Is the rep rate of the AC frequency set internally on the transformer
>     > > module?....If not, there must be an external timing component that's
>     > > making the thing run too fast.
>     > > A resonator?....A timing capacitor?
>     > > 
>     > > -- 
>     > > Scott Frye
>     > > 
>     > > Audio-fixation.net
>     > > 
>     > > Vermont
>     > >
>     >
>