Vintage Synth Repair

There's your problem right there, if you've plugged it in the wrong way round it will almost certainly damage internal components.

The 101 is pretty sensitive to wrong psu's. It also needs a regulated supply and so It specifies a Roland PSA adaptor. Most cheap adaptors are un-regulated.

Phil.


________________________________
From: Miguel Mendoza <miguel@filminteractive.es>
To: vintagesynthrepair@yahoogroups.com
Sent: Thu, 11 March, 2010 15:20:38
Subject: Re: [vintagesynthrepair] Roland SH 101 power adaptor problem

  
Hi Scott, thanks a lot for your answer. The polarity of 
the external power supply can be swaped changing the position of the tip. 
Sometimes I have plugged it in the wrong way and the result is that the unit 
doesn't work. Anyway, I'll check that.
 
Thanks!
 
Kind regards.
 
Miguel.
 


From: Scott S. 
Sent: Thursday, March 11, 2010 4:13 PM
To: vintagesynthrepair@ yahoogroups. com 
Subject: Re: [vintagesynthrepair ] Roland SH 101 power adaptor 
problem
  
Miguel, what type of power supplies are you using? I think the SH-101 is 
positive ground, unlike most other external power supplies. That probably is not 
your problem, but thought I would mention it here for reference. Roland could 
have put in diodes to protect it, or possibly a zener to correct the 
polarity?

Out of tune could just mean that it needs 
calibrating.

thx-shs


On Wed, Mar 3, 2010 at 2:17 PM, Miguel Mendoza <miguel@filminteract ive.es> wrote:

  
>Hello group, I'm having a problem with my Roland SH 
>  101:
> 
>When I turn it on, it takes some time to start 
>  working. After this, the synth is completly out of tune.
>After some time, the external power supply is getting 
>  very hot and I turn it off.
> 
>I tried with several external power adaptors with the 
>  same result.
> 
>I think that it could be a problem with the internal 
>  voltage regulator or a conderser but I would like to know if any of you 
>  know anything about this problem or have any idea of what it could 
>  be.
> 
>Thanks a lot in advance.
> 
>Regards.
> 
>Miguel.