Vintage Synth Repair

Hi,
Ok, so the voltage to the display circuit is correct so you need not worry
any further about the 11 volts as this is not an issue as far as the display
is concerned. It will be interesting to know in what way the coil failed.
Can you let us know what you find wrong with it.
You will remember you measured 11 volts AC coming from the transformer and
going into the ~ ~ of the rectifier D4.   D4 changes this AC into DC which
then charges the capacitor and smoothes the DC voltage.  If this capacitor
was not loaded by the rest of the circuit, the DC would measure at about 17
volts.  However, the capacitor is loaded by other parts of the organ so the
voltage is lower.  You have measured 11 volts DC which is reasonable.
Unless there are any other issues with the instrument then all is well.
Best regards,
John.
----- Original Message -----
From: "gil_we" <gil_we@...>
To: <vintagesynthrepair@yahoogroups.com>
Sent: Monday, September 04, 2006 7:55 PM
Subject: [vintagesynthrepair] Re: What causes bad unregulated voltage on the
power supply ?


> Thanks,
>
> The voltage feeding the transistors is 5v indeed.
> The display works ok so far (I'm also working on fixing the bad coil
> as well... to fit it back into my JX8P).
>
> So what you're saying is that there is a mistake in the
> schematics ?... Where does the 11v going into D4 is origin from ?
> Is that the transformer ?...
>
>
>