Thermal Dynamics MERLIN 6000 Service Manual page 43

pilot lead, under where the gas and coolant
hoses attach. The wire then goes to the Arc
Starter Box and on to the torch tip
• If voltage is incorrect, then check for an open
from that Power Supply to the Arc Starter Box
and then to the torch tip.
• If voltage is correct, then check for less than 2
vdc from TP1 to TP5. If voltage is correct, then
that Power Supply is in drag mode and the
Logic PCB is faulty.
2. Front Panel Current Control
If Remote Control (RC6010) is being used the Master
Power Supply Front Panel control is inactive. Go to
next step, Remote Current Control.
The Switching Control PCB outputs a voltage that is
used by the Current Control potentiometer. Make the
following voltage checks:
Check for 10 vdc on the high side of the potentiom-
eter from J10-17 to TP1 (ground).
Check for 3.3 vdc on the low side of the potentiom-
eter from J10-13 to TP1 (ground).
• If voltages are incorrect, then the Switching
Control PCB is faulty or there is a faulty rib-
bon cable.
The potentiometer wiper, J10-15, should vary between
3.3 and 10 vdc as the potentiometer is varied from
mininum to maximum position.
• If voltage is not correct, then the potentiometer
or ribbon cable is probably faulty. The fault
could also be a short on the Switching Control
PCB input.
The potentiometer wiper voltage, 3.3 to 10 vdc, is sent
to the Slave Power Supply from J50-4.
• If the wiper voltage is correct at J10-15 but not
at J50-4, then the Switching Control PCB is
faulty.
From J50-4 the wiper voltage is sent through the Iso-
lation PCB and Parallel Cable to the Slave Power Sup-
ply. Refer to Section 4.05-T, Isolation PCB and Paral-
lel Interface.
3. Remote Current Control
NOTE
Refer to Appendix XII for Current Control and Dis-
play Circuit Diagram.
Manual 0-2569
The Remote Control (RC 6010) has front panel con-
trols for OUTPUT AMPS and CSD. The upper and
lower limits of the current control range are set by the
POT HI (+10 vdc) and POT LOW (+3.3 vdc) signals
from J50-8 and J50-6 on the Switching Control PC
Board sent to the remote via the remote cable.
The CSD control upper limit is set by the wiper of the
OUTPUT AMPS control thus the CSD range is a per-
centage (%) of the main output. The wiper of the main
pot is sent through the normally closed CSD relay
contact out the remote cable to J7-18 on the Switching
Control PC Board. If CSD is enabled, indicated by
illuminating the 3 decimals in the display, then the
CSD wiper provides the current control signal to J7-
18.
Refer to Appendix XIII for Corner Slowdown
(CSD) Circuit Diagram.
If the OUTPUT AMPS control or the CSD control have
no effect on current level see if the panel control does,
if so, there may be a poor connection in the REMOTE
INSTALLED circuit between the remote and Switch-
ing Control PC Board. Check TP1 to J7-20, if it does
not measure less than 2v there is a faulty connection,
otherwise the Switching Control PC Board is faulty.
If the front panel control had no effect (which it
shouldn't) measure from TP1 to J7-18 while moving
the OUTPUT AMPS control from min to maximum.
The voltage at J7-18 should vary from 3.3v to 10 v. If
it does the Switching Control PC Board is faulty.
If voltage is incorrect at J7-18, check J50-8 for 10 v and
J50-6 for 3.3 v. If OK then the remote is defective or
the connections (remote cable or Merlin) harness are
open.
4. Remote AMPS Display
Refer to Appendix XII for Current Control and Dis-
play Circuit Diagram.
The Remote Control (RC 6010) AMPS displays the
following:
• Indicates the current control setting before cut-
ting (preview). Indicated by the right hand
decimal point being ON.
• Indicates the actual current while cutting.
• All three decimals on indicates the remote is
receiving the Corner Slowdown signal (CSD).
37
NOTE
NOTE
SERVICE TROUBLESHOOTING