Printronix P4280 - Page 141

5–59Replacement Procedures
68010
Microprocessor
DPU –001 DPU –002
DPU –003 DPU –004
Font –001
Font –003
Font –002
Font –004
68010
Controller
PAL
68010
Decode
PAL
Shared
Bus
PAL
Bus
Arbiter
PAL
DPMC
FTIC
MPU
PAL
PFC
PFC
NOVRAM
Static
RAM
PROM
PROM
64180
RTPU
64180
Decode
PAL
HI – 1 LO – 1
HI – 2 LO – 2
HI – 1
HI – 2
LO – 1
LO – 2
DPU PROM DPU PROM
DPU PROM DPU PROM
Font PROM Font PROM
Font PROMFont PROM
DPMC = Dot Plucker Memory Controller
FTIC = Fire T imer IC
NOVRAM = Nonvolatile Random Access Memory
PAL
= Programmable Array Logic
PFC = Paper Feed Controller
R TPU = Real T ime Processing Unit
LEGEND
DPU
LED *
DPU LED Indications at printer start–up:
*
RTPU
ON for 2 sec., then OFF = DPU OK
FLASHING 5 times / second = DPU RAM failure
FLASHING 1 time / second = DPU ROM failure
DPU = Data Processing Unit
MPU = Magnetic Pick–up
LED = Light–Emitting Diode
RTPU
LED
–001 –002
–003 –004
–001 –002
–003 –004
68010
&
64180
CLock
68010
&
64180
E2
Jumper
(Must be
present
or board
will not
work.)
PFC
CLock
Shared
Dynamic
RAM
PROM Kit: P/N 150122–901
Figure 5–24 . PROMs and Chips on the CCB