TM 5-3610-253-14
WARNING
Electrical shock hazard. You must stand on rubber matting as a protective
measure before performing this procedure. Death or serious injury may
occur.
Turn on power.
j.
(1) Turn main power switch to I position.
(2) Turn Star-Delta switch to Y position. After the main motor has
reached full speed, turn switch to
position.
(3) Press control power on switch.
k. Move backgauge forward or backward as required until the backgauge
position is displayed on the measurement display.
l.
With buttons not depressed, pins 19a and 19c should read +24 V, pins
18a and 18c should read 0 volts. Use ground post on SCU as ground.
m.
With buttons depressed, pins 18a and 18c should read +24 V, pins 19a
and 19c should read 0 volts. Use ground post on SCU as ground.
n.
If all indications are correct, the cutting buttons are functioning
properly.
o.
If none of these indications are correct, check PS 24 output (paragraph
cutting buttons and SCU unit.
If partial failure exists, check continuity of cutting buttons. If
p.
continuity checks good, problem may now be in cabling or SCU mother-
board. Check and replace as required (paragraph 5-40.34).
Turn off power.
q.
(1) Turn Star-Delta switch to Y position, then to O position.
(2) Turn main power switch to O position.
r.
Reinstall circuit board IAR.
s.
Reinstall front and rear electronics enclosure covers.
5-504
