E – Fuser Supply Fail - Printronix L5000 Series Maintenance Manual

1E – Fuser Supply Fail
1. Ensure that the alarm display LED ("FLS") for the flash power unit is
illuminated. If it is not, go to Step 3. (See illustration on page 6–52.)
2. Ensure that the fuser unit is properly installed, and that there are no
abnormalities in the high–voltage connection terminals.
3. Determine if the flash power unit is overheated. Check whether the LEDs "O.H
(FAN)" and "O.H (R)" are on; these are alarm display LEDs for the flash power
unit. If on, this indicates overheating.
If the flash power unit is overheated, let it cool for awhile (leave the power ON).
4. Check the flash power supply. Check whether the LEDs "O.V" and/or "CHG"
are on; these are alarm display LEDs for the flash power unit. If on, this indicates
a problem with the flash power supply; go to Step 6.
5. Check the flash voltage.
a. Put the positive lead of the digital multimeter on the V.CHECK (+) terminal
b. Measure the voltage, which should be 1.7V.
If voltage is not normal, adjust the flash power unit's variable resistor V.ADJ
until the voltage measured at the right becomes 1.7V. If you cannot attain 1.7V,
continue to the next step.
6. Check the MPU board.
a. Put the positive lead of the digital multimeter on pin 7 of CN10 on the MPU
b. Disconnect the CN11 jack from the flash power supply.
c. Short circuit the pins 7 and 8 of CN11 on the MPU board side.
7–66
CHECKLIST: ALARM LED
FUSER UNIT
FLASH POWER SUPPLY
FLASH VOLTAGE
MPU BOARD
of the flash power unit, and the negative lead on the V.CHECK (–) terminal.
board, and the negative lead on the SG.
Troubleshooting