Rhodes Chroma Polaris

You need to scope the output of the DAC / input to the S/H buffers to 
check if the DAC is working.  You should see a waveform that looks 
like a strange-bargraph (or S/H LFO).

My HS3140C blew and I searched-- the only replacement was from a 
military supplier and cost something like $150 or $175.  I think I 
blew it by messing up the power supply sequence while troubleshooting 
the power supply which is similar to what you did...

I ended up using the analog devices AN7538 DAC ($15) which has the 
similar specifications but a different pinout.  It wasn't hard to 
make an adapter using a stack of DIP sockets.  Datasheets for both 
parts are online.  You will also need to set the null-offset per the 
service manual when you are finished.

If that seems beyond your technical abilities, send me an email-- I 
can have a AN7538->HS3140C socket adapter PCB built for you for $75 
(including all parts) or $40 for just a PCB.

Thanks,
Ben



> I'm suspecting, at this point a blown DAC:
> 
> A)
> What I can do to be sure that DAC is working (or not working) ?
> 
> B) 
> Do you know of any DAC HS3140C reseller ?
> 
> thank you for your time
> 
> AT