Vintage Synth Repair

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 !!
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> Yahoo! Groups Links
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