Home Switch Problem

[john swift]

Hi Kev

using the photo's from post 3 and post 32

I have traced part of the supply circuit powering the opto-isolators




the track from the opto-isolators starts of on the underside of the board
then near to the 24V LED passes through a "via" (a plated through hole)and

then another "via" next to the missing B axis connector

the track ends at the + connector of the capacitor next to the LM317 regulator
the photo is not clear enough but I expect the capacitor + terminal is connected to the metal tab on the LM317 which is connected to the regulator output

the 1800 ohm and two 300 ohm resistors set the LM317 output to 10V

looking closer at the LM2576 switching regulator it has -5.0 at the end of its part number indicating its the 5V version
( LM2576S-5.0 = 5v ouput )

if a Via is open circuit the copper pads can be cleaned and a copper wire passed through and soldered to remak the connection

since the "24V LED" lights the only Via to check is lext to the LED

John

PS

check there is continuity from the limit switches 5 pin connector common terminal and the DC power in negative