[sdiy] Can I use two 1/4w resistors instead of one 1/2w ?

[Gil W.]

It appears that my response was too quick.

One I played with it for a few minutes, all notes I played got stuck and the control become frozen (no response for button clicks).

Now when I power it up all program LEDs light up and it makes a strange hum noise which becomes every 1 second. The PS voltages look ok though..... any suggestion ?






--- On Thu, 6/25/09, Gil W. <gil_we at yahoo.com> wrote:

> From: Gil W. <gil_we at yahoo.com>
> Subject: RE: [sdiy] Can I use two 1/4w resistors instead of one 1/2w ?
> To: "AlanNeedham" <Alan.Needham at centrica.com>
> Cc: "synth-diy at dropmix.xs4all.nl" <synth-diy at dropmix.xs4all.nl>
> Date: Thursday, June 25, 2009, 10:37 AM
> 
> Hi,
> 
> I replaced the resistor combination with a single 1.2K 1/2W
> and also cleaned the contacts between the transformer and
> the PS board. I also replaced the 470uf capacitor with a 63v
> (instead of the 50v I used) as the schematics calls for a
> 470uf/63v. I worked with the synth for more than 30 minutes
> without issues. Will let it run today for a few hours to
> make sure it is working ok.
> 
> Thanks !!
> 
> 
> 
> --- On Tue, 6/23/09, Needham, Alan <Alan.Needham at centrica.com>
> wrote:
> 
> > From: Needham, Alan <Alan.Needham at centrica.com>
> > Subject: RE: [sdiy] Can I use two 1/4w resistors
> instead of one 1/2w ?
> > To: "Gil W." <gil_we at yahoo.com>
> > Date: Tuesday, June 23, 2009, 3:40 PM
> > Simple tests first...
> > Unplug J2, J3 and J4. Power up the supply and measure
> each
> > regulator
> > output in turn, there are 3 off 5v rails and a 12v
> rail,
> > probably all
> > fine.
> > The bottom winding on the transformer should be
> giving
> > about 6vAC and
> > the resistor, R5, should remain cold.
> > Measure the voltage across C9 or C20 - I guess at
> about
> > 20v.
> > These tests will eliminate regulator problems and
> most
> > transformer
> > faults.
> > 
> > 
> > -----Original Message-----
> > From: Gil W. [mailto:gil_we at yahoo.com]
> > 
> > Sent: 23 June 2009 12:39
> > To: Magnus Danielson; synth-diy at dropmix.xs4all.nl;
> > Needham, Alan
> > Subject: RE: [sdiy] Can I use two 1/4w resistors
> instead of
> > one 1/2w ?
> > 
> > 
> > Of course, 
> > http://itec.uka.de/~buchty/eps-sch.pdf
> > 
> > This synth arrived with a severe power supply damage.
> It
> > had diode CR2
> > short out, Fuse F3 bad, C14 (470uf) blown (the top of
> the
> > cap swelled)
> > and the 1/2W resistor I mentioned (R5), fried and non
> > conductive.
> > 
> > I of course replaced them all (R5 is currently
> replaced
> > with the
> > combination of three resistors). The instrument works
> for a
> > few minutes
> > and than freezes...
> >      
> > 
> >
> _____________________________________________________________________
> > The information contained in or attached to this email
> is
> > intended only for the use of the individual or entity
> to
> > which it is addressed. If you are not the intended
> > recipient, or a person responsible for delivering it
> to the
> > intended recipient, you are not authorised to and must
> not
> > disclose, copy, distribute, or retain this message or
> any
> > part of it. It may contain information which is
> confidential
> > and/or covered by legal professional or other
> privilege (or
> > other rules or laws with similar effect in
> jurisdictions
> > outside England and Wales).
> > The views expressed in this email are not necessarily
> the
> > views of Centrica plc, and the company, its
> directors,
> > officers or employees make no representation or accept
> any
> > liability for its accuracy or completeness unless
> expressly
> > stated to the contrary.
> > 
> > Centrica plc
> > 
> > Registered office: Millstream, Maidenhead Road,
> Windsor,
> > Berkshire SL4 5GD
> > 
> > Registered in England and Wales No 3033654
> > 
> 
> 
>       
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>