Manitowoc 777 Service And Maintenance Manual

Reference Only
Manitowoc Published 10-01-2012, Control # 045-08 10-19
777 SERVICE MANUAL TROUBLESHOOTING
10
Problem 17
No swing operation, engine does not load.
POSSIBLE CAUSES
No voltage through control handle to controller; No voltage out of controller to pump EDC;
Wiring or switch is damaged; Pump or motor is damaged; Swing holding brake switch actuated.
CHECKS
Check Diagnostic Screen D2. (See Diagnostic Display topic in Section 3.) Does (bank 7)
change by 2 when enabling swing holding brake switch on control handle?
Yes
No
Does diagnostic display SWING screen (bank 1) approach 100%
handle control when handle is extended in either non-swinging
direction?
Check swing holding brake switch and
wiring to PC. (See Test 7.)
Ok
No Voltage
Voltage
Not Ok
Yes
No
Ok
Not Ok
Yes
No
Yes No
Does diagnostic display SWING screen (bank 2) approach 100% pump
control when handle is extended in either non-swinging direction?
Repair or replace
handle/ wiring.
Consult dealer/factory.
Repair or replace swing holding brake
switch and/or wiring to PC.
Check wiring connector at pump EDC.
Consult dealer/factory.
Connect or repair connector.
Manually stroke swing pump. (See Test
16.) Does platform rotate?
Isolate pump. Manually stroke pump. Is
system pressurized?
Use test plug adapter.
(See Test 13.) Is voltage
present at pump EDC?
Replace pump EDC.
Repair or replace motor.
Repair or replace wiring to
PC or consult dealer/factory.
Repair or replace pump.
When moving applicable handle fully in both
directions, does A1 diagnostic screen (bank 3) read
38 to 120 in lower or 136 to 215 in raise?
Yes
No
Repair or replace
control handle/wiring.
Yes No

Manitowoc 777 Specifications

General

Brand	Manitowoc
Model	777
Category	Construction Equipment
Language	English