Power supply 10-20V is stuck at 31.6V

[xavier60]

It does look like Vc and V+ pins 11 and 12 are connected. The LM723 is likely powered directly from the unregulated supply.

[Wind Tse]

Why you still using linear power supply?
Linear is heavy and old, you can try some cool.
DC Power Supply 30v 10a with good looking style just takes 60-90 EUR.

[Jwillis]

Why you still using linear power supply?
Linear is heavy and old, you can try some cool.
DC Power Supply 30v 10a with good looking style just takes 60-90 EUR.

Looks and style aren't the dominant factors in a power supply. Functionality is. Cheap Switching supplies lack the input and output filtering required for many applications. High frequency noise is non existent in a linear supply which is very important in audio and high RF applications.

[coromonadalix]

and poorly designed smps  doesn't accept  capacitive or inductives load  etc  .... they will bust pretty fast,  unless you buy really good brands  ...   not good looking ones


instead of going into a long non needed thread   

@OP   take time to make a schematic out of the psu, once put on a sheet you'll understand better, instead of doing many "guess timates"

[fmashockie]

Why you still using linear power supply?
Linear is heavy and old, you can try some cool.
DC Power Supply 30v 10a with good looking style just takes 60-90 EUR.

My guess is the OP didn't pick this supply.  From what I gather Trione makes ski-related equipment.  This power supply powers a motor for a ski service machine.  And yes, linear supplies still have their place and advantages over SMPS.  The same is true vis versa.

The LM723 can be a bit more difficult to use than some of its counterparts (LM7805, LM337, etc).  There are many design considerations that should be looked at.  https://electronicprojectsforfun.wordpress.com/power-supplies/a-collection-of-proper-design-practices-using-the-lm723-ic-regulator/

[floobydust]

OP, if you're still there and decide to fix this PSU - I would power it on the bench taken apart and carefully measure the LM723's voltages on each pin. That will tell us what is going on.

Did the one electrolytic leak a bit? The 470uF next to the power resistor array looks shady on the top.

A grinder does have generator-action and can backfeed into a power supply which would make it eat ordinary power supplies for breakfast.
(Note this may not be the "usual" 723 PSU with the LM393 and SOT23-5 IC hiding there, I think it's doing current sense.)