[sdiy] Prophet 5 -15v rail is shorting... Need advice

[Scott Gravenhorst]

"Gil W." <gil_we at yahoo.com> wrote:
>Hi all,
>
>I'm trying to solve a problem with a P5 I just got.
>
>It looks like the -15v rail on the main board is
>shorting.
>Each time I'll power it up, the 10uf tantalum
>capacitor which filters the -15v is getting fried and
>open (shorting) immediately.
>
>Any ideas where to start looking at ? Any common parts
>on the P5 with are known to short over time ?
>
>Thanks for the help !

I'm not a Prophet guy, but...

It sounds like the -15v is going lower than -15v and past the tantalum's
rating.  That would cause the tantalum to blow.  So the regulator (if it has
one) may not be regulating?  If the -15v supply line can be disconnected from
the synth, then you could power it up without the tantalum and see what the
voltage is and figure out why it's too negative.


-- ScottG

-------------------------------------------------------------

-- Scott Gravenhorst
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