MX-GBX1. Service Manual - Sharp Copying Equipment Service Manual (repair manual). Page 40

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The Troubleshooting Guide Chart that follows is arranged in order of the normal operational sequence. 
When a malfunction occurs, read down the SYMPTOM column until you reach the appropriate description 
for your symptom. Read the corresponding PROBABLE CAUSE and then perform the recommended 
procedure in the CORRECTIVE ACTION column. 

 

SYMPTOM 

PROBABLE CAUSE 

CORRECTIVE ACTION 

No indication of power 
 

Not plugged in 
 

Check to ensure that power cord is 
properly connected to the machine 
as well as the supply voltage.  
 
Check the power supplied from the 
outlet 
 

No indication of power, 
Unit is plugged in 
 
 
 
 
 
 

Main Control Board, a minimum of 2 of 
the 3 LED’s on this board should be lit, 
if not, board is bad 
 
Display Panel or Cable 
 
 

Replace Main Control Board 
 
 
 
Inspect or replace 
 
Inspect or replace 
 
Inspect or replace 
 
Change the jumper to the proper line 
voltage 

Machine will not start, READY 
LED is ON 
 
 
 
 
 
 
 

Check Power Supply Board LED, if not 
lit, board is bad 
 
Check Main Control Board LED’s, if a 
minimum of two of the three are not lit, 
board is bad 
 
Door is not closed or properly making 
the interlock 
 

Power down Punch and then Multi-
function printer 
 
Power up Punch then Multi-function 
printer 
 
Inspect cable connections, replace 
board as needed 
 
Inspect cable connections, replace 
board as needed 
 
Inspect and correct 

Paper Jam LED is lit, customer / 
operator has been unable to 
locate the jam 
 
Paper Jam, not able to find any 
large sheets, removed sheets 
are torn 
 

A Sensor is blocked 
 
 
Suspect a small piece of paper is 
hidden somewhere in the paper path 

Separate the SmartPunch from the 
Multi-function printer and the 
Finisher, clean out the entire paper 
path 
 
Unplug sensor one at a time to see 
which one is active.