Vintage Synth Repair

HI,
I  replaced some times ago my display on my K5000W because of the high-pitch tone coming from the DC/DC converter.
If you replace the display with a led backlight (like this one: http://www.zinguy.com/lcdpage.htm), you don't need the DC/DC converter anymore ; the 5V DC output from the power supply will suffice.
I remember that my DC/DC converter was a SUMIDA one, but I don't remember the reference.

Maybe you'll find detailed information on the K5000 group:
http://launch.groups.yahoo.com/group/K5000/

/Greg

--- In vintagesynthrepair@yahoogroups.com, Daniel Forró <dan.for@...> wrote:
>
> 
> I have now small problem with power supply inside my Kawai K5000W.
> 
> I moved to Japan from Europe and there are two different voltages in  
> my studio (220 V and 100 V) which can be dangerous. By my mistake  
> Kawai got 220 V, not 100, because I changed internal connection on  
> PSU when repaired FDD, and after returning the instrument back to its  
> place in my studio I didn't realized it and used 220 V (cabel end was  
> the same).
> 
> Fortunately transformer survived, 17 V symmetric section works. 5 V  
> section gives only 0.5 V on output. Zener diode D8 is OK after  
> measuring outside the PCB, so I hope that all following PCB's with  
> digital circuitry survived... This diode is unfortunately the only  
> protection.
> 
> So it looks I need to change these components:
> 
> F2 - ICP-N25 (IC Protector)
> U2 - Mitsubishi M5291P (DC/DC Switching Supply Converter/Regulator)
> Q1 - Sanyo 2SA1641 S/T (transistor)
> maybe  Q3 - Sanyo 2SD1246 S/T (transistor)
> 
> I tried different shops on net, Japanese, American (of course  
> Digikey, Mouser...), but they haven't these components. Neither I  
> could find some substitutions (maybe U2 can be substituted by  
> MC34063AP1, I have to compare datasheets. Does somebody know  
> equivalent types?
> 
> Could somebody please recommend me some good shop anywhere? I'lll be  
> grateful for any help as K5000 is one of my favorite instruments...  
> Of course even after PS repair there's a chance digital circuitry  
> didn't survived despite that double protection and Zener... In that  
> case I must buy whole instrument, or at least K5000R rack version...
> 
> Service department of Kawai Japan headquarters in Hamamatsu refused  
> repair, I have called there. They don't do any repair or sell parts  
> for instruments older than 10 years, maybe it's some new law in Japan  
> because Yamaha has same policy now.
> 
> Thanks for any hint.
> 
> Daniel Forro
>