Cabinet power
switch inoper-
able.

Rear access door
not properly 
closed; safety 
interlock not 
engaged.

Ensure rear access door is 
closed. 

Cabinet fan(s)
do not operate 
(controller 
powers up.)

a. AC power
source faulty.



b. Fan power cable 
disconnected.

c. Cabinet AC 
power faulty.














d. Faulty fans.

a. Check main power breakers;
reset if tripped.  Check 
line power input (line 
power cable, house fuse).

b. Check AC power connection 
at fan.

c. Check fan power cable with 
voltmeter.  If no power 
present, troubleshoot as 
follows:

(1) Check circuit break-
ers at power trans-
former (bottom of 
controller).  Reset 
if tripped.

(2) Check AC harness to fans for contin-
uity.  Call Unimation
Field Service if faulty.


d. Check fan power cable with 
voltmeter.  If power is 
present, replace fans.

POWER ON indi-
cator does not 
light (con-
troller powers
up). 

Defective POWER 
ON indicator 
bulb.

Replace POWER ON indicator
bulb.

Controller
does not power
up (POWER ON
indicator does 
not light; 
cooling fans
do not oper-
ate; no ini-
tialization 
message).

a. Controller
power cord dis-
connected.

b. Faulty CX (J145)
electrical connections.



c. AC power source 
circuit breaker 
tripped.


d. Defective con-
troller POWER 
ON switch or AC
power cord.






e. Defective 115/
24V power supply. 

a. Check controller power
cord.  Reconnect if neces-
sary.  

b. Check arm cables for proper 
connections.  Ensure J145 
is installed and properly 
jumpered.

c. Unplug terminal power line.
Check CB2 circuit breaker
on rear panel of trans-
former chamber.

d. Unplug controller power
line.  Check continuity in 
POWER ON switch.  Replace
switch if no continuity de-
tected.  Check for conti-
nuity in AC power cord;
replace if no continuity 
detected.


e. Check for presence of 24 V
 at 115/24V power supply.  
Replace faulty power supply 
(power supply has a relay 
controlling 110 VAC to 
logic power).

VDT does not 
power up 
(no cursor;
on-off indi-
cator does not light.

a. Terminal power
cord disconnect-
ed. 

b. Terminal circuit
breaker tripped.


c. Circuit breaker 
tripped.


d. Defective ter-
minal POWER ON
switch.



e. Defective
terminal.

a. Check terminal power cord.
Reconnect if necessary. 

b. Unplug terminal power line.
Remove top cover; reset 
circuit breaker at rear of 
chassis.

c. Check CB2 circuit breaker 
on rear panel of trans-
former chamber.

d. Unplug terminal power line.
Check for continuity across
POWER ON switch.  Replace 
switch if no continuity
detected.

e. Replace with operable 
terminal.

No
initialization 
message (con-
troller powers 
up; VDT 
powers up).

a. Loose terminal 
connections.




b. Operator error.





c. Board(s) not 
securely seated.

d. Blown fuse in 
low voltage 
power supply.















e. Defective
LSI 11-73 micro-
processor board.

f. Defective "A"
interface board.

g. Defective quad
serial board.

h. Defective CMOS 
memory board.

i. Loose capacitor 
in low voltage 
power supply.  

a. Check terminal connections 
at back of terminal and at 
back of controller for 
tightness. Tighten as 
necessary.

b. Begin startup sequence 
again.  Terminal must be on 
with a visible cursor be-
fore turning controller 
power on.

c. Check boards in card cage 
for proper seating.

d. Check connector P138 for
following voltage levels:

WIRE 160 = +24 VDC
Wire 37 = +12 VDC
Wire 50 = 0 VDC
Wire 38 = -12 vdc
Wire 41 = +5 VDC

NOTE

No voltage readings indi-
cate blown power supply 
fuse.  Loss of single volt-
age indicates blown fuse 
for that voltage.  Replace 
fuse (paragraph 5-5-2-1).

e.  Replace defective board.



f. Replace defective board.


g. Replace defective board.
(board located at J34).

h. Replace defective board
(board at slot J32).

i. Inspect capacitor; resolder 
if loose.  Replace low 
voltage power supply if 
necessary.

Garbled 
initialization 
message (VDT 
powers up, 
controller 
powers up).

a. Loose terminal 
connections.




b. Board(s) not 
securely seated.

c. Defective 
board(s).

a. Check terminal connections 
at back of terminal and 
at back of controller for 
tightness.  Tighten as 
necessary.  

b. Check boards in card cage 
for proper seating.

c. Replace boards in the fol-
lowing sequence, checking 
if problem persists after 
each replacement.

(1) Quad serial board
(board at slot J34).

(2) "A" interface board.

(3) LSI-11/73 CPU board.

(4) "B" interface board.

NOTE

If garbled message 
persists, call Unimation
Field Service.

ARM POWER does
not come on 
(controller 
powers up).

a. System not ini-
tialized.


b. System in TEACH 
mode.

c. Faulty CX (J145)
electrical 
connections.


d. Controller in 
"remote" CX



e. VAL in FATAL
condition due 
to hardware 
fault.



f. Brake release
switch not in 
NORMAL position.

g. E-STOP circuit
open.




h. Defective "B"
interface board.

i. Defective "C" 
interface board. 


j. Defective CX
module.

k. Defective arm
cable.




l. Boards installed
improperly.

m. Defective "A" 
interface board.

n. Defective 
LSI-11/73
processor board.

o. Defective CMOS 
board.

a. Check that system is ini-
tialized.  Initialize if
necessary.

b. Place Mode Select switch 
to PAUSE.

c. Check arm cables for proper
connections.  Ensure J145 
is installed and properly 
jumpered.

d. Switch to "LOCAL" mode or
have external equipment 
activate appropriate arm
power CX inputs.

e. Input STATUS command at 
VDT to determine VAL state.  
Check FAULT (F) LED on 
control panel.  Refer to 
Table 5-12, "Fault LED is 
Lit."

f. Set brake release switch to 
NORMAL.


g. Check E-STOP buttons on
controller front and teach 
pendant.  Ensure that j145 
is properly jumpered if 
remote E-STOP is not used.

h. Replace defective "B" 
interface board.

i. Check board seating; re-
place "C" interface board
if defective.

j. Replace defective CX board.


k. Remove arm cable.  Check 
for continuity on all 
lines.  Replace arm cable
if continuity breaks are 
found.

l. Check board installation.


m. Replace defective "A" in-
terface board.

n. Replace defective board.



o. Replace defective board.


NOTE

If arm power problem per-
sists, call Unimation 
Field Service Department.

VDT does not 
respond cor-
rectly or
system does 
not respond 
correctly to 
VDT 
(controller 
powers up;
VDT powers 
up).

a. Operator error





b. Terminal 
settings incor-
rect.


c. Loose terminal
connections.




d. Defective cable




e. Quad serial 
board not seat-
ed securely or 
not properly 
jumpered.



f. LSI-11/73 CPU 
board faulty

g. Blown fuse in 
low voltage 
power supply.
















h. "A" interface 
board not seated 
securely.


i. CMOS memory 
board not 
securely seated.

k. Defective I/O
module.

a. Ensure that VDT keyboard
lockout switch is set to 
KEYBOARD ENABLE. Check
error messages (refer to 
TABLE 5-11).

b. Refer Unimation Visual 
Display Terminal manual,
Paragraph A.1.5 for VDT 
settings.

c. Check terminal connections
at back of terminal and at 
back of controller for 
tightness.  Tighten as 
necessary.

d. Check terminal cable wiring
for continuity.  If any
wire lacks continuity,
replace terminal cable.

e. Check seating of quad se-
rial board (DLV-11J)
(board at slot J34).  
Check jumpering (refer to 
drawing 7223c39 in Electri-
cal drawing set 394W1).


f. Check seating of LSI-11/73
CPU board.

g. Check connector P138 for 
the following voltage
levels:

Wire 160 = +24 VDC
Wire 37 = +12 VDC
Wire 50 = 0 VDC
Wire 38 = -12 VDC
Wire 41 = +5 VDC

NOTE

No voltage readings indi-
cate blown power supply 
fuse.  Loss of single volt-
age indicates blown fuse 
for that voltage.  Replace
fuse (paragraph 5-5-2-1).

h. Check seating of "A" inter-
face board.



i. Check seating of CMOS 
memory board.


k. Disconnect all I/O modules
and attempt to use VDT.  
If VDT communications are 
correct, shut down system 
and reconnect one I/O 
module.  Continue this pro-
cedure until original 
problem reappears.  
Replace defective I/O 
module.

 NOTE

If terminal response
problem persists, call 
Unimation Field Service.

Messages are 
displayed 
very slowly 
with excessive 
time between 
characters.

Incorrect clock
setting upon 
startup or after
error recovery 
on VAL 2.X and 
higher. 

Replace JOINT 1.0 software 
on "B" interface board with 
JOINT 1.1 software.

Teach pendant 
does not dis-
play message.

a. Loose or faulty
interconnection 
between pendant 
and controller.

b. Faulty teach 
pendant. 

c. faulty low 
voltage power 
supply.
















d. Faulty quad 
serial interface 
board.

a. Inspect connection at 
controller.  Check for 
damage to cable or 
connectors.

b. Replace teach pendant.


c. Check connector P138 for 
the following voltage 
levels:

Wire 160 = +24 VDC
Wire 37  = +12 VDC
Wire 50  = 0 VDC
Wire 38  = -12 VDC
Wire 41  =  +5 VDC


NOTE 
No voltage readings indi-
cate blown power supply 
fuse.  Loss of single volt-
age indicates blown fuse
for that voltage.  Replace 
fuse (paragraph 5-5-2-1).

d. Check seating; replace 
faulty quad serial board.