Vintage Synth Repair

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
>   >
>