User Guide

Problem Action
3 Replace the power-supply assembly. See Power supply.
4 Replace the dc controller. See
Dc controller PCA.
Note:
The fan only operates during the initial startup and while printing, and when the
temperature inside the printer is too high. If the temperature is too high, the fan
turns on to cool the inside of the printer.
The fan works, but the control-panel
display is blank.
1 Print an engine test. Engine-test page.
2 If the engine test is successful, perform the following steps, in order.
● Reseat the control panel and formatter connector. See
Control-panel
assembly and Formatter assembly .
● Replace the control-panel cable. See
Control-panel assembly.
● Replace the control-panel assembly. See
Control-panel assembly.
● (HP Laserjet 4200 and 4300 Series printers only) Replace the
firmware DIMM. See Firmware DIMM (LJ 4200/4300 only).
● Replace the formatter. See
Formatter assembly .
3 If the engine test is not successful, remove the formatter and attempt to
perform the engine test again. If the engine test is successful with the
formatter removed, replace the formatter. See
Formatter assembly . If the test
is not successful with the formatter removed, replace the dc controller PCA.
See
Dc controller PCA.
Table 7-2 Power-on defect or blank display (continued)
308 7 Troubleshooting