wrote in message
oups.com...
On Nov 8, 11:24 am, Eeyore

wrote:
wrote:
On Nov 8, 4:49 am, "Arfa Daily"
wrote:
Well, I would have to say that it certainly indicates
that you are not
chasing down any kind of permanent 'short' on your 5v
rail. So now that you
know where the 5v rail comes off the end of the LM317
(was it ?), can you
disconnect it from that point, leave the fuses out of the
12 and 30v feeds,
and hook the unit back to line power, with a 5v fuse in
place ? Measure the
IN, SET and OUT pins of the '317 to see what you get, and
if you get a
correct 5v on the OUT pin[...]

If the voltage isn't correct (e.g. 4.8-5.2V) at that point
(but the
fuse isn't blown) tack a 470 ohm resistor from the OUT pin
to GND. The LM317
has a load regulation spec of 10 mA, and a minimum
operating current of
~1mA (for low Vi-Vo); the adjust resistors may not be small
enough to draw
this much. And don't isolate the regulator by lifting the
OUT pin, or
you'll lose the adjust resistors.

It's not an LM317 though, it's some funny STM part, an L387.

Oh. 5mA then, at least if it's the same as the L387A:

http://www.st.com/stonline/products/...1337/l387a.pdf
It's a fixed 5V regulator, so no Vset resistors.


whew , less complications is a welcome occurance to me
more good news please
thanks,
rob