[sdiy] Prophet 5 power supply issues solved - fuse resistor frying now

[Gil W.]

OK,

So what seemed to solve the crazy voltage problems and
tantalum shorts, was simply using higher voltage
tantalum caps ! 

Although the ones I initially used are rated 25v, 
it seems they still could not hold the 15v rails
efficiently, and simply got fried !

The fuse resistor fried simply because the shorting of
one tantalum filter cap, caused another cap to short
out as well, that I didn't manage to replace. That cap
as well created a short over the +15v rail, causing
the resistor to fry...

Once I had correct and stable +15/-15 voltages, I
started to experienced spontaneous restarting and all
kind of strange behaviors happening to the control
panel after a minute of work. I checked the voltages
and found that the 5.6v rail shows only 5v. I then
switched the 5v regulator on the main board back to
the original regulator and it seems to solve that
issue (I replaced the regulator at some point,
thinking it might help solving the the positive
voltage problems).

So now I finally seem to have a working Prophet 5 !

I didn't want to let it run more than half an hour at
once, as the heat sink gets hot as hell. I think I'll
have to either get a larger heat sink, or simply place
two small CPU fans on it to cool it down

What is still left now is calibrating the unit,
restoring and leveling the keyboard and of course
building the bottom and rear panel and jacks that the
synth is missing (this is how I got it...)

Thanks all !


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