General Troubleshooting 4-5
POST Hard Fault Messages
POST indicates a hard fault by displaying a message on the Control Panel and 
blinking the fault code on the health and Control Panel LEDs. There are long and 
short blinks. A long blink is worth 5 and a short blink is worth 1. As an example, a 
blink pattern flashed as long, long, short, short, represents fault code 5+5+1+1=12, 
indicating a failure in the CPU interrupt test. Along with the blinking LEDs, the failed 
test also displays as:
POWER ON SELF TEST ERROR
12:CPU INTERRUPTS
CALL SERVICE SUPPORT
The exception to this reporting scheme is a RAM test error. The Boot Loader executes 
a RAM test prior to loading POST. If the Boot Loader encounters a RAM error, POST 
does not load.
 
Fault Isolation
Isolate a fault to the print engine or Image Processor Board by printing an Engine Test 
Print (
page 5-9).
■ If the printer successfully prints the Print Engine Test Print, replace the Image 
Processor Board (
page 8-98).
■ If the Printer fails to print the Print Engine Test Print, troubleshoot the print 
engine starting with the AC power supply on (
page 4-14).
Hard Error LED Blink Patterns and Messages
LED Blink 
Pattern
Control Panel 
Message
Action
1 RAM ERROR No RAM present, or faulty RAM. Alternate 1/2 second 
interval blink at Control Panel and Health LEDs if the 
controller has initialized the FPGA. Otherwise, only the 
Health LED blinks.
1+1 Control Panel disconnected or defective.
5+5 10: EEPROM 1. Switch Off printer power. 
2. Remove and re-install the NVRAM EEPROM. 
3. Switch On printer power. 
4. If the error message persists, replace NVRAM , and 
then the Image Processor Board.
5+5+1+1 12: CPU 
INTERRUPTS
Replace Image Processor Board (page 8-98).
5+5+5+1 16: Min RAM Add additional RAM memory.
5+5+5+5+1+1 22: Engine 
Command
If a failure is detected, Reseat Controller Board is displayed 
(
page 4-12).