Faulty Heater Rod - Star Micronics LS-5 SERIES Technical Manual

3-5. Faulty Heater Rod

Step
1 Check parts with different specifications for problems with
usage, defective installation, breakage, and deformation.
• Main parts to be checked:
(1) Fuser assy, (2) Temp. sensor assy, (3) Heater rod
(4) MCU PCB, (5) LVPS assy, (6) ROS assy
(7) CRU sensor PCB
2 (Check heater rod)
100-115V models: Is there conductivity between J101-2PIN
220-240V models: Is there conductivity between J101-3PIN
3 (Check LVPS)
Is there 4.2 VDC between J11-1PIN
• Check before the output is stopped by the no-load status of the
LVPS assy (within 30 seconds of the power being turned on).
4 (Check heater rod ON signal) *1
Is the voltage between P/J11-1PIN
when the interlock switch is on, and 3.7 VDC when the
interlock switch is off?
• Check while the fuser assy is still cold.
5 (Check power supply of heater rod ON signal) *1 *2
Is 5 VDC being supplied between P/J11-5PIN
6 (Check power supply of heater rod ON signal) *2
Disconnect the connector (P/J12) from the MCU PCB, and see
if the heater rod lights up when the power supply is turned on.
7 (Check power supply of heater rod ON signal) *2
Disconnect the connector (P/J15) from the MCU PCB, and see
if the heater rod lights up when the power supply is turned on.
8 (Check heater rod)
Disconnect the heater rod, and see if there conductivity be-
tween the terminals on the two ends of the rod.
9 (Check temp. sensor assy)
100-115V models: Is there conductivity between the terminals
220-240V models: Is there conductivity between the terminals
10 (Check thermostat and fuse)
Check to see if the thermostat is open, and if the fuse has melted.
*1: Check with the connector (P/J111) disconnected from the HVPS.
*2: The "5VDC-LD" which is the LD power supply for the LD assy of the ROS assy also doubles as the heater rod ON signal.
Check
↔
J101-6PIN?
↔
J101-6PIN?
↔
J11-2PIN?
↔
P/J11-2PIN 0 VDC
↔
of the J101-2PIN harness, and between the
terminals of the J101-6PIN harness?
of the J101-3PIN harness, and between the
terminals of the J101-6PIN harness?
– 101 –
TROUBLESHOOTING
YES
To step 2
To step 3
To step 4
To step 5
Replace LVPS
P/J11-2PIN? assy.
Replace ROS
assy.
Replace CRU
sensor PCB.
To step 9
To step 10
In order to find out
why the thermostat
is open or the fuse
has melted, first
replace the fuser
assy, and then go
back to Step 1 and
check again.
Measure
NO
Replace or
reinstall.
To step 8
Replace LVPS
assy.
To section 3-6
To step 6
To step 7
Replace MCU
PCB.
Replace heater
rod.
Replace temp.
sensor assy.
Replace fuser
assy.