Seig C3 CNC spindle problem

looking at the circuit diagram I linked to

this a simplified diagram of the low voltage supplies to the control circuit

Attachment 24675

R17 is the large resistor on the board

its value is 15 K (15000 ohms)
in parallel with a 100K resistor that gives you a total of 13K

if you get more than 13K then R17 will need replacing
has R17 changed colour ?

Attachment 24676

the resistors drops the rectified mains down to 22V at terminal K4 is linked to K3

with K3 & K4 open circuit I would of expected you to have 200V DC

if terminal K4 was shorted to earth
a number of semiconductors will need checking
starting with Z1 the 22V zenner and the 78L12 regulator IC

John

The machine in question is in fact my X3 mill and not the C3 lathe.