Vintage Synth Repair

Thanks !

I uploaded the schematics to the Files section here...

Are you refering to D5 ?.... But isn't it supposed to control the DC 
voltage rather then the unregulated voltage ?

Thanks for any advice !!



--- In vintagesynthrepair@yahoogroups.com, "John Brewer" <john@...> 
wrote:
>
> I have had a similar problem on another piece of equipment.  The 
bridge
> rectifier was the culprit.  Can you scan and e-mail me the power 
supply
> circuit and I will have a look for you.
> JohnB
> ----- Original Message -----
> From: "gil_we" <gil_we@...>
> To: <vintagesynthrepair@yahoogroups.com>
> Sent: Sunday, August 20, 2006 12:22 AM
> Subject: [vintagesynthrepair] What causes bad unregulated voltage 
on the
> power supply ?
> 
> 
> > I got a Roland MKS70 of which the Power Supply unregulated 
voltage rail
> > is too high. The schematics says there should be +7v but I read 
11V
> > when the DMM is set to DC and 28v when set to AC !
> >
> > This fits with the fact that the display of that unit is 
overbright,
> > showing all characters at once....
> >
> > But what can cause the unregulated voltage to be incorrect ?
> > could this be bad regulators in the PS unit ??
> >
> > I already replaced all capacitors in the PS.
> >
> > Thanks all !!
> >
> >
> >
> >
> >
> >
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > --
> > Internal Virus Database is out-of-date.
> > Checked by AVG Free Edition.
> > Version: 7.1.394 / Virus Database: 268.10.7/409 - Release Date: 
04/08/06
> >
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>