[sdiy] Advice?: Powering up a vintage keyboard after several years

[Barry Klein]

What do you think the odds are that I'm going to have an issue?
Say on a Memorymoog.  The damn thing has so many CMOS parts that croak for 
whatever reason.  Was it because the owner powered it up infrequently?
Was it because of weak output caps in the supplies?  I tend to think the 
parts just crap out over time because of manufacturing process flaws. I 
tested the output caps with my LC102 on the memorymoogs (3) that I repaired 
and they were fine - the parts just went bad.  Otherwise, bad caps, use the 
synth multiple times you will just as likely see failures with a lot of use 
rather than after 5 years I would assume...
Like on the Andromeda's I had been looking at recently - the CPU just seems 
to die and needs to be replaced.
Have you really seen power supply faults in a pretest like you suggest? 
Without a load I wonder if the issues even show up.
I guess I'll let you guys know the score after I try them all....

Barry


-----Original Message----- 
From: Michael E Caloroso
Sent: Tuesday, October 11, 2016 7:17 PM
To: Barry Klein
Cc: synth-diy at dropmix.xs4all.nl
Subject: Re: [sdiy] Advice?: Powering up a vintage keyboard after several 
years

If it's any synth with CMOS or CEM or SSM ICs in it, verify the power
supply FIRST.  If a rail is missing or over spec it can blow these
things.  The last thing you want are blown CEM/SSM ICs.

MC

On 10/11/16, Barry Klein <barryklein at cox.net> wrote:
> Well, that’s me....
> If the consensus is just plug it in I’m good but if it is check the 
> supplies
> first....  memorymoogs, prophet 5, lesser synths...  I’d just leave them 
> off
> – don’t need the added grief right now.
> No way am I going to tweak up the memorymoog supplies and go through
> calibration of them again... at least not now.
> Maybe the Variac is just a thing for tube-based things like old ham sets 
> or
> guitar amps?
> I have 2 (transistor(ized) ham tranceivers and a Drake receiver that I 
> need
> to try too.
>
>
> Barry
>
>
> From: Jason Proctor
> Sent: Tuesday, October 11, 2016 6:35 PM
> To: David G Dixon
> Cc: Barry Klein ; synth-diy DIY
> Subject: Re: [sdiy] Advice?: Powering up a vintage keyboard after several
> years
>
> have someone who knows what they're doing check at least the PSU first?
>
>
>
> On Tue, Oct 11, 2016 at 6:25 PM, David G Dixon <dixon at mail.ubc.ca> wrote:
>
>   Plug that shit in!
>
>
>
> ----------------------------------------------------------------------------
>     From: Synth-diy [mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf
> Of Barry Klein
>     Sent: Tuesday, October 11, 2016 5:14 AM
>     To: synth-diy DIY
>     Subject: [sdiy] Advice?: Powering up a vintage keyboard after several
> years
>
>
>     I am going through the stuff in my garage.  I have several vintage
> synths – some worth quite a bit now – and they haven’t been powered in at
> least 5 years.
>     What would you recommend – advancing on a Variac, or just plug it in?
>     Barry
>
>
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