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

[Gil W.]

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
>